]> scripts.mit.edu Git - autoinstalls/wordpress.git/blobdiff - wp-includes/query.php
WordPress 4.0
[autoinstalls/wordpress.git] / wp-includes / query.php
index cf3cc1e29b38bc447118e4983446227956831c39..39a22c7dc5ca25411d8d3477ea6418a5a3668232 100644 (file)
@@ -2,8 +2,8 @@
 /**
  * WordPress Query API
  *
- * The query API attempts to get which part of WordPress to the user is on. It
- * also provides functionality to getting URL query information.
+ * The query API attempts to get which part of WordPress the user is on. It
+ * also provides functionality for getting URL query information.
  *
  * @link http://codex.wordpress.org/The_Loop More information on The Loop.
  *
  * @since 1.5.0
  * @uses $wp_query
  *
- * @param string $var The variable key to retrieve.
+ * @param string $var       The variable key to retrieve.
+ * @param mixed  $default   Value to return if the query variable is not set. Default ''.
  * @return mixed
  */
-function get_query_var($var) {
+function get_query_var( $var, $default = '' ) {
        global $wp_query;
 
-       return $wp_query->get($var);
+       return $wp_query->get( $var, $default );
+}
+
+/**
+ * Retrieve the currently-queried object. Wrapper for $wp_query->get_queried_object()
+ *
+ * @uses WP_Query::get_queried_object
+ *
+ * @since 3.1.0
+ * @access public
+ *
+ * @return object
+ */
+function get_queried_object() {
+       global $wp_query;
+       return $wp_query->get_queried_object();
+}
+
+/**
+ * Retrieve ID of the current queried object. Wrapper for $wp_query->get_queried_object_id()
+ *
+ * @uses WP_Query::get_queried_object_id()
+ *
+ * @since 3.1.0
+ * @access public
+ *
+ * @return int
+ */
+function get_queried_object_id() {
+       global $wp_query;
+       return $wp_query->get_queried_object_id();
 }
 
 /**
@@ -56,9 +87,8 @@ function set_query_var($var, $value) {
  * @param string $query
  * @return array List of posts
  */
-function &query_posts($query) {
-       unset($GLOBALS['wp_query']);
-       $GLOBALS['wp_query'] =& new WP_Query();
+function query_posts($query) {
+       $GLOBALS['wp_query'] = new WP_Query();
        return $GLOBALS['wp_query']->query($query);
 }
 
@@ -73,23 +103,22 @@ function &query_posts($query) {
  * @uses $wp_query
  */
 function wp_reset_query() {
-       unset($GLOBALS['wp_query']);
-       $GLOBALS['wp_query'] =& $GLOBALS['wp_the_query'];
+       $GLOBALS['wp_query'] = $GLOBALS['wp_the_query'];
        wp_reset_postdata();
 }
 
 /**
  * After looping through a separate query, this function restores
- * the $post global to the current post in the main query
+ * the $post global to the current post in the main query.
  *
  * @since 3.0.0
  * @uses $wp_query
  */
 function wp_reset_postdata() {
        global $wp_query;
-       if ( !empty($wp_query->post) ) {
-               $GLOBALS['post'] = $wp_query->post;
-               setup_postdata($wp_query->post);
+
+       if ( isset( $wp_query ) ) {
+               $wp_query->reset_postdata();
        }
 }
 
@@ -98,182 +127,174 @@ function wp_reset_postdata() {
  */
 
 /**
- * Is query requesting an archive page.
+ * Is the query for an existing archive page?
  *
+ * Month, Year, Category, Author, Post Type archive...
+ *
+ * @see WP_Query::is_archive()
  * @since 1.5.0
  * @uses $wp_query
  *
- * @return bool True if page is archive.
+ * @return bool
  */
 function is_archive() {
        global $wp_query;
 
-       return $wp_query->is_archive;
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
+               return false;
+       }
+
+       return $wp_query->is_archive();
 }
 
 /**
- * Is query requesting an attachment page.
+ * Is the query for an existing post type archive page?
  *
- * @since 2.0.0
+ * @see WP_Query::is_post_type_archive()
+ * @since 3.1.0
  * @uses $wp_query
  *
- * @return bool True if page is attachment.
+ * @param mixed $post_types Optional. Post type or array of posts types to check against.
+ * @return bool
  */
-function is_attachment() {
+function is_post_type_archive( $post_types = '' ) {
        global $wp_query;
 
-       return $wp_query->is_attachment;
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
+               return false;
+       }
+
+       return $wp_query->is_post_type_archive( $post_types );
 }
 
 /**
- * Is query requesting an author page.
+ * Is the query for an existing attachment page?
  *
- * If the $author parameter is specified then the check will be expanded to
- * include whether the queried author matches the one given in the parameter.
- * You can match against integers and against strings.
+ * @see WP_Query::is_attachment()
+ * @since 2.0.0
+ * @uses $wp_query
  *
- * If matching against an integer, the ID should be used of the author for the
- * test. If the $author is an ID and matches the author page user ID, then
- * 'true' will be returned.
+ * @param mixed $attachment Attachment ID, title, slug, or array of such.
+ * @return bool
+ */
+function is_attachment( $attachment = '' ) {
+       global $wp_query;
+
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
+               return false;
+       }
+
+       return $wp_query->is_attachment( $attachment );
+}
+
+/**
+ * Is the query for an existing author archive page?
  *
- * If matching against strings, then the test will be matched against both the
- * nickname and user nicename and will return true on success.
+ * If the $author parameter is specified, this function will additionally
+ * check if the query is for one of the authors specified.
  *
+ * @see WP_Query::is_author()
  * @since 1.5.0
  * @uses $wp_query
  *
- * @param string|int $author Optional. Is current page this author.
- * @return bool True if page is author or $author (if set).
+ * @param mixed $author Optional. User ID, nickname, nicename, or array of User IDs, nicknames, and nicenames
+ * @return bool
  */
-function is_author($author = '') {
+function is_author( $author = '' ) {
        global $wp_query;
 
-       if ( !$wp_query->is_author )
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
                return false;
+       }
 
-       if ( empty($author) )
-               return true;
-
-       $author_obj = $wp_query->get_queried_object();
-
-       $author = (array) $author;
-
-       if ( in_array( $author_obj->ID, $author ) )
-               return true;
-       elseif ( in_array( $author_obj->nickname, $author ) )
-               return true;
-       elseif ( in_array( $author_obj->user_nicename, $author ) )
-               return true;
-
-       return false;
+       return $wp_query->is_author( $author );
 }
 
 /**
- * Whether current page query contains a category name or given category name.
+ * Is the query for an existing category archive page?
  *
- * The category list can contain category IDs, names, or category slugs. If any
- * of them are part of the query, then it will return true.
+ * If the $category parameter is specified, this function will additionally
+ * check if the query is for one of the categories specified.
  *
+ * @see WP_Query::is_category()
  * @since 1.5.0
  * @uses $wp_query
  *
- * @param string|array $category Optional.
+ * @param mixed $category Optional. Category ID, name, slug, or array of Category IDs, names, and slugs.
  * @return bool
  */
-function is_category($category = '') {
+function is_category( $category = '' ) {
        global $wp_query;
 
-       if ( !$wp_query->is_category )
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
                return false;
+       }
 
-       if ( empty($category) )
-               return true;
-
-       $cat_obj = $wp_query->get_queried_object();
-
-       $category = (array) $category;
-
-       if ( in_array( $cat_obj->term_id, $category ) )
-               return true;
-       elseif ( in_array( $cat_obj->name, $category ) )
-               return true;
-       elseif ( in_array( $cat_obj->slug, $category ) )
-               return true;
-
-       return false;
+       return $wp_query->is_category( $category );
 }
 
 /**
- * Whether the current page query has the given tag slug or contains tag.
+ * Is the query for an existing tag archive page?
+ *
+ * If the $tag parameter is specified, this function will additionally
+ * check if the query is for one of the tags specified.
  *
+ * @see WP_Query::is_tag()
  * @since 2.3.0
  * @uses $wp_query
  *
- * @param string|array $slug Optional. Single tag or list of tags to check for.
+ * @param mixed $tag Optional. Tag ID, name, slug, or array of Tag IDs, names, and slugs.
  * @return bool
  */
-function is_tag( $slug = '' ) {
+function is_tag( $tag = '' ) {
        global $wp_query;
 
-       if ( !$wp_query->is_tag )
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
                return false;
+       }
 
-       if ( empty( $slug ) )
-               return true;
-
-       $tag_obj = $wp_query->get_queried_object();
-
-       $slug = (array) $slug;
-
-       if ( in_array( $tag_obj->slug, $slug ) )
-               return true;
-
-       return false;
+       return $wp_query->is_tag( $tag );
 }
 
 /**
- * Whether the current query is for the given taxonomy and/or term.
+ * Is the query for an existing taxonomy archive page?
+ *
+ * If the $taxonomy parameter is specified, this function will additionally
+ * check if the query is for that specific $taxonomy.
  *
- * If no taxonomy argument is set, returns true if any taxonomy is queried.
- * If the taxonomy argument is passed but no term argument, returns true
- *    if the taxonomy or taxonomies in the argument are being queried.
- * If both taxonomy and term arguments are passed, returns true
- *    if the current query is for a term contained in the terms argument
- *    which has a taxonomy contained in the taxonomy argument.
+ * If the $term parameter is specified in addition to the $taxonomy parameter,
+ * this function will additionally check if the query is for one of the terms
+ * specified.
  *
+ * @see WP_Query::is_tax()
  * @since 2.5.0
  * @uses $wp_query
  *
- * @param string|array $taxonomy Optional. Taxonomy slug or slugs to check in current query.
- * @param int|array|string $term. Optional. A single or array of, The term's ID, Name or Slug
+ * @param mixed $taxonomy Optional. Taxonomy slug or slugs.
+ * @param mixed $term Optional. Term ID, name, slug or array of Term IDs, names, and slugs.
  * @return bool
  */
 function is_tax( $taxonomy = '', $term = '' ) {
-       global $wp_query, $wp_taxonomies;
-
-       $queried_object = $wp_query->get_queried_object();
-       $tax_array = array_intersect(array_keys($wp_taxonomies), (array) $taxonomy);
-       $term_array = (array) $term;
+       global $wp_query;
 
-       if ( !$wp_query->is_tax )
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
                return false;
+       }
 
-       if ( empty( $taxonomy ) )
-               return true;
-
-       if ( empty( $term ) ) // Only a Taxonomy provided
-               return isset($queried_object->taxonomy) && count( $tax_array ) && in_array($queried_object->taxonomy, $tax_array);
-
-       return isset($queried_object->term_id) &&
-                       count(array_intersect(
-                               array($queried_object->term_id, $queried_object->name, $queried_object->slug),
-                               $term_array
-                       ));
+       return $wp_query->is_tax( $taxonomy, $term );
 }
 
 /**
  * Whether the current URL is within the comments popup window.
  *
+ * @see WP_Query::is_comments_popup()
  * @since 1.5.0
  * @uses $wp_query
  *
@@ -282,12 +303,18 @@ function is_tax( $taxonomy = '', $term = '' ) {
 function is_comments_popup() {
        global $wp_query;
 
-       return $wp_query->is_comments_popup;
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
+               return false;
+       }
+
+       return $wp_query->is_comments_popup();
 }
 
 /**
- * Whether current URL is based on a date.
+ * Is the query for an existing date archive?
  *
+ * @see WP_Query::is_date()
  * @since 1.5.0
  * @uses $wp_query
  *
@@ -296,12 +323,18 @@ function is_comments_popup() {
 function is_date() {
        global $wp_query;
 
-       return $wp_query->is_date;
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
+               return false;
+       }
+
+       return $wp_query->is_date();
 }
 
 /**
- * Whether current blog URL contains a day.
+ * Is the query for an existing day archive?
  *
+ * @see WP_Query::is_day()
  * @since 1.5.0
  * @uses $wp_query
  *
@@ -310,26 +343,39 @@ function is_date() {
 function is_day() {
        global $wp_query;
 
-       return $wp_query->is_day;
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
+               return false;
+       }
+
+       return $wp_query->is_day();
 }
 
 /**
- * Whether current page query is feed URL.
+ * Is the query for a feed?
  *
+ * @see WP_Query::is_feed()
  * @since 1.5.0
  * @uses $wp_query
  *
+ * @param string|array $feeds Optional feed types to check.
  * @return bool
  */
-function is_feed() {
+function is_feed( $feeds = '' ) {
        global $wp_query;
 
-       return $wp_query->is_feed;
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
+               return false;
+       }
+
+       return $wp_query->is_feed( $feeds );
 }
 
 /**
- * Whether current page query is comment feed URL.
+ * Is the query for a comments feed?
  *
+ * @see WP_Query::is_comments_feed()
  * @since 3.0.0
  * @uses $wp_query
  *
@@ -338,12 +384,27 @@ function is_feed() {
 function is_comment_feed() {
        global $wp_query;
 
-       return $wp_query->is_comment_feed;
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
+               return false;
+       }
+
+       return $wp_query->is_comment_feed();
 }
 
 /**
- * Whether current page query is the front of the site.
+ * Is the query for the front page of the site?
+ *
+ * This is for what is displayed at your site's main URL.
  *
+ * Depends on the site's "Front page displays" Reading Settings 'show_on_front' and 'page_on_front'.
+ *
+ * If you set a static page for the front page of your site, this function will return
+ * true when viewing that page.
+ *
+ * Otherwise the same as @see is_home()
+ *
+ * @see WP_Query::is_front_page()
  * @since 2.5.0
  * @uses is_home()
  * @uses get_option()
@@ -351,22 +412,29 @@ function is_comment_feed() {
  * @return bool True, if front of site.
  */
 function is_front_page() {
-       // most likely case
-       if ( 'posts' == get_option('show_on_front') && is_home() )
-               return true;
-       elseif ( 'page' == get_option('show_on_front') && get_option('page_on_front') && is_page(get_option('page_on_front')) )
-               return true;
-       else
+       global $wp_query;
+
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
                return false;
+       }
+
+       return $wp_query->is_front_page();
 }
 
 /**
- * Whether current page view is the blog homepage.
+ * Is the query for the blog homepage?
+ *
+ * This is the page which shows the time based blog content of your site.
  *
- * This is the page which is showing the time based blog content of your site
- * so if you set a static page for the front page of your site then this will
- * only be true on the page which you set as the "Posts page" in Reading Settings.
+ * Depends on the site's "Front page displays" Reading Settings 'show_on_front' and 'page_for_posts'.
  *
+ * If you set a static page for the front page of your site, this function will return
+ * true only on the page you set as the "Posts page".
+ *
+ * @see is_front_page()
+ *
+ * @see WP_Query::is_home()
  * @since 1.5.0
  * @uses $wp_query
  *
@@ -375,12 +443,18 @@ function is_front_page() {
 function is_home() {
        global $wp_query;
 
-       return $wp_query->is_home;
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
+               return false;
+       }
+
+       return $wp_query->is_home();
 }
 
 /**
- * Whether current page query contains a month.
+ * Is the query for an existing month archive?
  *
+ * @see WP_Query::is_month()
  * @since 1.5.0
  * @uses $wp_query
  *
@@ -389,52 +463,45 @@ function is_home() {
 function is_month() {
        global $wp_query;
 
-       return $wp_query->is_month;
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
+               return false;
+       }
+
+       return $wp_query->is_month();
 }
 
 /**
- * Whether query is page or contains given page(s).
+ * Is the query for an existing single page?
  *
- * Calls the function without any parameters will only test whether the current
- * query is of the page type. Either a list or a single item can be tested
- * against for whether the query is a page and also is the value or one of the
- * values in the page parameter.
+ * If the $page parameter is specified, this function will additionally
+ * check if the query is for one of the pages specified.
  *
- * The parameter can contain the page ID, page title, or page name. The
- * parameter can also be an array of those three values.
+ * @see is_single()
+ * @see is_singular()
  *
+ * @see WP_Query::is_page()
  * @since 1.5.0
  * @uses $wp_query
  *
- * @param mixed $page Either page or list of pages to test against.
+ * @param mixed $page Page ID, title, slug, or array of such.
  * @return bool
  */
-function is_page($page = '') {
+function is_page( $page = '' ) {
        global $wp_query;
 
-       if ( !$wp_query->is_page )
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
                return false;
+       }
 
-       if ( empty($page) )
-               return true;
-
-       $page_obj = $wp_query->get_queried_object();
-
-       $page = (array) $page;
-
-       if ( in_array( $page_obj->ID, $page ) )
-               return true;
-       elseif ( in_array( $page_obj->post_title, $page ) )
-               return true;
-       else if ( in_array( $page_obj->post_name, $page ) )
-               return true;
-
-       return false;
+       return $wp_query->is_page( $page );
 }
 
 /**
- * Whether query contains multiple pages for the results.
+ * Is the query for paged result and not for the first page?
  *
+ * @see WP_Query::is_paged()
  * @since 1.5.0
  * @uses $wp_query
  *
@@ -443,32 +510,18 @@ function is_page($page = '') {
 function is_paged() {
        global $wp_query;
 
-       return $wp_query->is_paged;
-}
-
-/**
- * Whether the current page was created by a plugin.
- *
- * The plugin can set this by using the global $plugin_page and setting it to
- * true.
- *
- * @since 1.5.0
- * @global bool $plugin_page Used by plugins to tell the query that current is a plugin page.
- *
- * @return bool
- */
-function is_plugin_page() {
-       global $plugin_page;
-
-       if ( isset($plugin_page) )
-               return true;
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
+               return false;
+       }
 
-       return false;
+       return $wp_query->is_paged();
 }
 
 /**
- * Whether the current query is preview of post or page.
+ * Is the query for a post or page preview?
  *
+ * @see WP_Query::is_preview()
  * @since 2.0.0
  * @uses $wp_query
  *
@@ -477,12 +530,18 @@ function is_plugin_page() {
 function is_preview() {
        global $wp_query;
 
-       return $wp_query->is_preview;
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
+               return false;
+       }
+
+       return $wp_query->is_preview();
 }
 
 /**
- * Whether the current query post is robots.
+ * Is the query for the robots file?
  *
+ * @see WP_Query::is_robots()
  * @since 2.1.0
  * @uses $wp_query
  *
@@ -491,12 +550,18 @@ function is_preview() {
 function is_robots() {
        global $wp_query;
 
-       return $wp_query->is_robots;
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
+               return false;
+       }
+
+       return $wp_query->is_robots();
 }
 
 /**
- * Whether current query is the result of a user search.
+ * Is the query for a search?
  *
+ * @see WP_Query::is_search()
  * @since 1.5.0
  * @uses $wp_query
  *
@@ -505,70 +570,74 @@ function is_robots() {
 function is_search() {
        global $wp_query;
 
-       return $wp_query->is_search;
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
+               return false;
+       }
+
+       return $wp_query->is_search();
 }
 
 /**
- * Whether the current page query is single page.
+ * Is the query for an existing single post?
  *
- * The parameter can contain the post ID, post title, or post name. The
- * parameter can also be an array of those three values.
+ * Works for any post type, except attachments and pages
  *
- * This applies to other post types, attachments, pages, posts. Just means that
- * the current query has only a single object.
+ * If the $post parameter is specified, this function will additionally
+ * check if the query is for one of the Posts specified.
  *
+ * @see is_page()
+ * @see is_singular()
+ *
+ * @see WP_Query::is_single()
  * @since 1.5.0
  * @uses $wp_query
  *
- * @param mixed $post Either post or list of posts to test against.
+ * @param mixed $post Post ID, title, slug, or array of such.
  * @return bool
  */
-function is_single($post = '') {
+function is_single( $post = '' ) {
        global $wp_query;
 
-       if ( !$wp_query->is_single )
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
                return false;
+       }
 
-       if ( empty($post) )
-               return true;
-
-       $post_obj = $wp_query->get_queried_object();
-
-       $post = (array) $post;
-
-       if ( in_array( $post_obj->ID, $post ) )
-               return true;
-       elseif ( in_array( $post_obj->post_title, $post ) )
-               return true;
-       elseif ( in_array( $post_obj->post_name, $post ) )
-               return true;
-
-       return false;
+       return $wp_query->is_single( $post );
 }
 
 /**
- * Whether is single post, is a page, or is an attachment.
+ * Is the query for an existing single post of any post type (post, attachment, page, ... )?
  *
+ * If the $post_types parameter is specified, this function will additionally
+ * check if the query is for one of the Posts Types specified.
+ *
+ * @see is_page()
+ * @see is_single()
+ *
+ * @see WP_Query::is_singular()
  * @since 1.5.0
  * @uses $wp_query
  *
- * @param string|array $post_types Optional. Post type or types to check in current query.
+ * @param mixed $post_types Optional. Post Type or array of Post Types
  * @return bool
  */
-function is_singular($post_types = '') {
+function is_singular( $post_types = '' ) {
        global $wp_query;
 
-       if ( empty($post_types) || !$wp_query->is_singular )
-               return $wp_query->is_singular;
-
-       $post_obj = $wp_query->get_queried_object();
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
+               return false;
+       }
 
-       return in_array($post_obj->post_type, (array) $post_types);
+       return $wp_query->is_singular( $post_types );
 }
 
 /**
- * Whether the query contains a time.
+ * Is the query for a specific time?
  *
+ * @see WP_Query::is_time()
  * @since 1.5.0
  * @uses $wp_query
  *
@@ -577,12 +646,18 @@ function is_singular($post_types = '') {
 function is_time() {
        global $wp_query;
 
-       return $wp_query->is_time;
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
+               return false;
+       }
+
+       return $wp_query->is_time();
 }
 
 /**
- * Whether the query is a trackback.
+ * Is the query for a trackback endpoint call?
  *
+ * @see WP_Query::is_trackback()
  * @since 1.5.0
  * @uses $wp_query
  *
@@ -591,12 +666,18 @@ function is_time() {
 function is_trackback() {
        global $wp_query;
 
-       return $wp_query->is_trackback;
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
+               return false;
+       }
+
+       return $wp_query->is_trackback();
 }
 
 /**
- * Whether the query contains a year.
+ * Is the query for an existing year archive?
  *
+ * @see WP_Query::is_year()
  * @since 1.5.0
  * @uses $wp_query
  *
@@ -605,25 +686,54 @@ function is_trackback() {
 function is_year() {
        global $wp_query;
 
-       return $wp_query->is_year;
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
+               return false;
+       }
+
+       return $wp_query->is_year();
 }
 
 /**
- * Whether current page query is a 404 and no results for WordPress query.
+ * Is the query a 404 (returns no results)?
  *
+ * @see WP_Query::is_404()
  * @since 1.5.0
  * @uses $wp_query
  *
- * @return bool True, if nothing is found matching WordPress Query.
+ * @return bool
  */
 function is_404() {
        global $wp_query;
 
-       return $wp_query->is_404;
+       if ( ! isset( $wp_query ) ) {
+               _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1' );
+               return false;
+       }
+
+       return $wp_query->is_404();
+}
+
+/**
+ * Is the query the main query?
+ *
+ * @since 3.3.0
+ *
+ * @return bool
+ */
+function is_main_query() {
+       if ( 'pre_get_posts' === current_filter() ) {
+               $message = sprintf( __( 'In <code>%1$s</code>, use the <code>%2$s</code> method, not the <code>%3$s</code> function. See %4$s.' ),
+                       'pre_get_posts', 'WP_Query::is_main_query()', 'is_main_query()', __( 'http://codex.wordpress.org/Function_Reference/is_main_query' ) );
+               _doing_it_wrong( __FUNCTION__, $message, '3.7' );
+       }
+
+       global $wp_query;
+       return $wp_query->is_main_query();
 }
 
 /*
- * The Loop.  Post loop control.
+ * The Loop. Post loop control.
  */
 
 /**
@@ -729,22 +839,49 @@ function the_comment() {
 class WP_Query {
 
        /**
-        * Query string
+        * Query vars set by the user
         *
         * @since 1.5.0
         * @access public
-        * @var string
+        * @var array
         */
-       var $query;
+       public $query;
 
        /**
-        * Query search variables set by the user.
+        * Query vars, after parsing
         *
         * @since 1.5.0
         * @access public
         * @var array
         */
-       var $query_vars = array();
+       public $query_vars = array();
+
+       /**
+        * Taxonomy query, as passed to get_tax_sql()
+        *
+        * @since 3.1.0
+        * @access public
+        * @var object WP_Tax_Query
+        */
+       public $tax_query;
+
+       /**
+        * Metadata query container
+        *
+        * @since 3.2.0
+        * @access public
+        * @var object WP_Meta_Query
+        */
+       public $meta_query = false;
+
+       /**
+        * Date query container
+        *
+        * @since 3.7.0
+        * @access public
+        * @var object WP_Date_Query
+        */
+       public $date_query = false;
 
        /**
         * Holds the data for a single object that is queried.
@@ -755,7 +892,7 @@ class WP_Query {
         * @access public
         * @var object|array
         */
-       var $queried_object;
+       public $queried_object;
 
        /**
         * The ID of the queried object.
@@ -764,7 +901,7 @@ class WP_Query {
         * @access public
         * @var int
         */
-       var $queried_object_id;
+       public $queried_object_id;
 
        /**
         * Get post database query.
@@ -773,7 +910,7 @@ class WP_Query {
         * @access public
         * @var string
         */
-       var $request;
+       public $request;
 
        /**
         * List of posts.
@@ -782,7 +919,7 @@ class WP_Query {
         * @access public
         * @var array
         */
-       var $posts;
+       public $posts;
 
        /**
         * The amount of posts for the current query.
@@ -791,7 +928,7 @@ class WP_Query {
         * @access public
         * @var int
         */
-       var $post_count = 0;
+       public $post_count = 0;
 
        /**
         * Index of the current item in the loop.
@@ -800,7 +937,7 @@ class WP_Query {
         * @access public
         * @var int
         */
-       var $current_post = -1;
+       public $current_post = -1;
 
        /**
         * Whether the loop has started and the caller is in the loop.
@@ -809,16 +946,16 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $in_the_loop = false;
+       public $in_the_loop = false;
 
        /**
-        * The current post ID.
+        * The current post.
         *
         * @since 1.5.0
         * @access public
-        * @var int
+        * @var WP_Post
         */
-       var $post;
+       public $post;
 
        /**
         * The list of comments for current post.
@@ -827,7 +964,7 @@ class WP_Query {
         * @access public
         * @var array
         */
-       var $comments;
+       public $comments;
 
        /**
         * The amount of comments for the posts.
@@ -836,7 +973,7 @@ class WP_Query {
         * @access public
         * @var int
         */
-       var $comment_count = 0;
+       public $comment_count = 0;
 
        /**
         * The index of the comment in the comment loop.
@@ -845,7 +982,7 @@ class WP_Query {
         * @access public
         * @var int
         */
-       var $current_comment = -1;
+       public $current_comment = -1;
 
        /**
         * Current comment ID.
@@ -854,16 +991,18 @@ class WP_Query {
         * @access public
         * @var int
         */
-       var $comment;
+       public $comment;
 
        /**
-        * Amount of posts if limit clause was not used.
+        * The amount of found posts for the current query.
+        *
+        * If limit clause was not used, equals $post_count.
         *
         * @since 2.1.0
         * @access public
         * @var int
         */
-       var $found_posts = 0;
+       public $found_posts = 0;
 
        /**
         * The amount of pages.
@@ -872,7 +1011,7 @@ class WP_Query {
         * @access public
         * @var int
         */
-       var $max_num_pages = 0;
+       public $max_num_pages = 0;
 
        /**
         * The amount of comment pages.
@@ -881,7 +1020,7 @@ class WP_Query {
         * @access public
         * @var int
         */
-       var $max_num_comment_pages = 0;
+       public $max_num_comment_pages = 0;
 
        /**
         * Set if query is single post.
@@ -890,7 +1029,7 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_single = false;
+       public $is_single = false;
 
        /**
         * Set if query is preview of blog.
@@ -899,7 +1038,7 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_preview = false;
+       public $is_preview = false;
 
        /**
         * Set if query returns a page.
@@ -908,7 +1047,7 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_page = false;
+       public $is_page = false;
 
        /**
         * Set if query is an archive list.
@@ -917,7 +1056,7 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_archive = false;
+       public $is_archive = false;
 
        /**
         * Set if query is part of a date.
@@ -926,7 +1065,7 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_date = false;
+       public $is_date = false;
 
        /**
         * Set if query contains a year.
@@ -935,7 +1074,7 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_year = false;
+       public $is_year = false;
 
        /**
         * Set if query contains a month.
@@ -944,7 +1083,7 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_month = false;
+       public $is_month = false;
 
        /**
         * Set if query contains a day.
@@ -953,7 +1092,7 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_day = false;
+       public $is_day = false;
 
        /**
         * Set if query contains time.
@@ -962,7 +1101,7 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_time = false;
+       public $is_time = false;
 
        /**
         * Set if query contains an author.
@@ -971,7 +1110,7 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_author = false;
+       public $is_author = false;
 
        /**
         * Set if query contains category.
@@ -980,7 +1119,7 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_category = false;
+       public $is_category = false;
 
        /**
         * Set if query contains tag.
@@ -989,7 +1128,7 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_tag = false;
+       public $is_tag = false;
 
        /**
         * Set if query contains taxonomy.
@@ -998,7 +1137,7 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_tax = false;
+       public $is_tax = false;
 
        /**
         * Set if query was part of a search result.
@@ -1007,7 +1146,7 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_search = false;
+       public $is_search = false;
 
        /**
         * Set if query is feed display.
@@ -1016,7 +1155,7 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_feed = false;
+       public $is_feed = false;
 
        /**
         * Set if query is comment feed display.
@@ -1025,7 +1164,7 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_comment_feed = false;
+       public $is_comment_feed = false;
 
        /**
         * Set if query is trackback.
@@ -1034,7 +1173,7 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_trackback = false;
+       public $is_trackback = false;
 
        /**
         * Set if query is blog homepage.
@@ -1043,7 +1182,7 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_home = false;
+       public $is_home = false;
 
        /**
         * Set if query couldn't found anything.
@@ -1052,7 +1191,7 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_404 = false;
+       public $is_404 = false;
 
        /**
         * Set if query is within comments popup window.
@@ -1061,7 +1200,16 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_comments_popup = false;
+       public $is_comments_popup = false;
+
+       /**
+        * Set if query is paged
+        *
+        * @since 1.5.0
+        * @access public
+        * @var bool
+        */
+       public $is_paged = false;
 
        /**
         * Set if query is part of administration page.
@@ -1070,7 +1218,7 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_admin = false;
+       public $is_admin = false;
 
        /**
         * Set if query is an attachment.
@@ -1079,7 +1227,7 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_attachment = false;
+       public $is_attachment = false;
 
        /**
         * Set if is single, is a page, or is an attachment.
@@ -1088,7 +1236,7 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_singular = false;
+       public $is_singular = false;
 
        /**
         * Set if query is for robots.
@@ -1097,7 +1245,7 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_robots = false;
+       public $is_robots = false;
 
        /**
         * Set if query contains posts.
@@ -1108,7 +1256,51 @@ class WP_Query {
         * @access public
         * @var bool
         */
-       var $is_posts_page = false;
+       public $is_posts_page = false;
+
+       /**
+        * Set if query is for a post type archive.
+        *
+        * @since 3.1.0
+        * @access public
+        * @var bool
+        */
+       public $is_post_type_archive = false;
+
+       /**
+        * Stores the ->query_vars state like md5(serialize( $this->query_vars ) ) so we know
+        * whether we have to re-parse because something has changed
+        *
+        * @since 3.1.0
+        * @access private
+        */
+       private $query_vars_hash = false;
+
+       /**
+        * Whether query vars have changed since the initial parse_query() call. Used to catch modifications to query vars made
+        * via pre_get_posts hooks.
+        *
+        * @since 3.1.1
+        * @access private
+        */
+       private $query_vars_changed = true;
+
+       /**
+        * Set if post thumbnails are cached
+        *
+        * @since 3.2.0
+        * @access public
+        * @var bool
+        */
+        public $thumbnails_cached = false;
+
+       /**
+        * Cached list of search stopwords.
+        *
+        * @since 3.7.0
+        * @var array
+        */
+       private $stopwords;
 
        /**
         * Resets query flags to false.
@@ -1118,8 +1310,9 @@ class WP_Query {
         * @since 2.0.0
         * @access private
         */
-       function init_query_flags() {
+       private function init_query_flags() {
                $this->is_single = false;
+               $this->is_preview = false;
                $this->is_page = false;
                $this->is_archive = false;
                $this->is_date = false;
@@ -1137,12 +1330,14 @@ class WP_Query {
                $this->is_trackback = false;
                $this->is_home = false;
                $this->is_404 = false;
+               $this->is_comments_popup = false;
                $this->is_paged = false;
                $this->is_admin = false;
                $this->is_attachment = false;
                $this->is_singular = false;
                $this->is_robots = false;
                $this->is_posts_page = false;
+               $this->is_post_type_archive = false;
        }
 
        /**
@@ -1151,7 +1346,7 @@ class WP_Query {
         * @since 1.5.0
         * @access public
         */
-       function init() {
+       public function init() {
                unset($this->posts);
                unset($this->query);
                $this->query_vars = array();
@@ -1160,6 +1355,15 @@ class WP_Query {
                $this->post_count = 0;
                $this->current_post = -1;
                $this->in_the_loop = false;
+               unset( $this->request );
+               unset( $this->post );
+               unset( $this->comments );
+               unset( $this->comment );
+               $this->comment_count = 0;
+               $this->current_comment = -1;
+               $this->found_posts = 0;
+               $this->max_num_pages = 0;
+               $this->max_num_comment_pages = 0;
 
                $this->init_query_flags();
        }
@@ -1170,8 +1374,8 @@ class WP_Query {
         * @since 1.5.0
         * @access public
         */
-       function parse_query_vars() {
-               $this->parse_query('');
+       public function parse_query_vars() {
+               $this->parse_query();
        }
 
        /**
@@ -1183,7 +1387,7 @@ class WP_Query {
         * @param array $array Defined query variables.
         * @return array Complete query variables with undefined ones filled in empty.
         */
-       function fill_query_vars($array) {
+       public function fill_query_vars($array) {
                $keys = array(
                        'error'
                        , 'm'
@@ -1208,6 +1412,7 @@ class WP_Query {
                        , 'tag'
                        , 'cat'
                        , 'tag_id'
+                       , 'author'
                        , 'author_name'
                        , 'feed'
                        , 'tb'
@@ -1218,18 +1423,21 @@ class WP_Query {
                        , 'preview'
                        , 's'
                        , 'sentence'
+                       , 'fields'
+                       , 'menu_order'
                );
 
                foreach ( $keys as $key ) {
-                       if ( !isset($array[$key]))
+                       if ( !isset($array[$key]) )
                                $array[$key] = '';
                }
 
-               $array_keys = array('category__in', 'category__not_in', 'category__and', 'post__in', 'post__not_in',
-                       'tag__in', 'tag__not_in', 'tag__and', 'tag_slug__in', 'tag_slug__and');
+               $array_keys = array( 'category__in', 'category__not_in', 'category__and', 'post__in', 'post__not_in',
+                       'tag__in', 'tag__not_in', 'tag__and', 'tag_slug__in', 'tag_slug__and', 'post_parent__in', 'post_parent__not_in',
+                       'author__in', 'author__not_in' );
 
                foreach ( $array_keys as $key ) {
-                       if ( !isset($array[$key]))
+                       if ( !isset($array[$key]) )
                                $array[$key] = array();
                }
                return $array;
@@ -1241,20 +1449,109 @@ class WP_Query {
         * @since 1.5.0
         * @access public
         *
-        * @param string|array $query
+        * @param string|array $query {
+        *     Optional. Array or string of Query parameters.
+        *
+        *     @type int          $attachment_id           Attachment post ID. Used for 'attachment' post_type.
+        *     @type int|string   $author                  Author ID, or comma-separated list of IDs.
+        *     @type string       $author_name             User 'user_nicename'.
+        *     @type array        $author__in              An array of author IDs to query from.
+        *     @type array        $author__not_in          An array of author IDs not to query from.
+        *     @type bool         $cache_results           Whether to cache post information. Default true.
+        *     @type int|string   $cat                     Category ID or comma-separated list of IDs (this or any children).
+        *     @type array        $category__and           An array of category IDs (AND in).
+        *     @type array        $category__in            An array of category IDs (OR in, no children).
+        *     @type array        $category__not_in        An array of category IDs (NOT in).
+        *     @type string       $category_name           Use category slug (not name, this or any children).
+        *     @type int          $comments_per_page       The number of comments to return per page.
+        *                                                 Default 'comments_per_page' option.
+        *     @type int|string   $comments_popup          Whether the query is within the comments popup. Default empty.
+        *     @type array        $date_query              An associative array of WP_Date_Query arguments.
+        *                                                 {@see WP_Date_Query::__construct()}
+        *     @type int          $day                     Day of the month. Default empty. Accepts numbers 1-31.
+        *     @type bool         $exact                   Whether to search by exact keyword. Default false.
+        *     @type string|array $fields                  Which fields to return. Single field or all fields (string),
+        *                                                 or array of fields. 'id=>parent' uses 'id' and 'post_parent'.
+        *                                                 Default all fields. Accepts 'ids', 'id=>parent'.
+        *     @type int          $hour                    Hour of the day. Default empty. Accepts numbers 0-23.
+        *     @type bool         $ignore_sticky_posts     Whether to ignore sticky posts or not. Setting this to false
+        *                                                 excludes stickies from 'post__in'. Accepts 1|true, 0|false.
+        *                                                 Default 0|false.
+        *     @type int          $m                       Combination YearMonth. Accepts any four-digit year and month
+        *                                                 numbers 1-12. Default empty.
+        *     @type string       $meta_compare            Comparison operator to test the 'meta_value'.
+        *     @type string       $meta_key                Custom field key.
+        *     @type array        $meta_query              An associative array of WP_Meta_Query arguments.
+        *                                                 {@see WP_Meta_Query->queries}
+        *     @type string       $meta_value              Custom field value.
+        *     @type int          $meta_value_num          Custom field value number.
+        *     @type int          $menu_order              The menu order of the posts.
+        *     @type int          $monthnum                The two-digit month. Default empty. Accepts numbers 1-12.
+        *     @type string       $name                    Post slug.
+        *     @type bool         $nopaging                Show all posts (true) or paginate (false). Default false.
+        *     @type bool         $no_found_rows           Whether to skip counting the total rows found. Enabling can improve
+        *                                                 performance. Default false.
+        *     @type int          $offset                  The number of posts to offset before retrieval.
+        *     @type string       $order                   Designates ascending or descending order of posts. Default 'DESC'.
+        *                                                 Accepts 'ASC', 'DESC'.
+        *     @type string       $orderby                 Sort retrieved posts by parameter. One or more options can be
+        *                                                 passed. To use 'meta_value', or 'meta_value_num',
+        *                                                 'meta_key=keyname' must be also be defined. Default 'date'.
+        *                                                 Accepts 'none', 'name', 'author', 'date', 'title', 'modified',
+        *                                                 'menu_order', 'parent', 'ID', 'rand', 'comment_count'.
+        *     @type int          $p                       Post ID.
+        *     @type int          $page                    Show the number of posts that would show up on page X of a
+        *                                                 static front page.
+        *     @type int          $paged                   The number of the current page.
+        *     @type int          $page_id                 Page ID.
+        *     @type string       $pagename                Page slug.
+        *     @type string       $perm                    Show posts if user has the appropriate capability.
+        *     @type array        $post__in                An array of post IDs to retrieve, sticky posts will be included
+        *     @type string       $post_mime_type          The mime type of the post. Used for 'attachment' post_type.
+        *     @type array        $post__not_in            An array of post IDs not to retrieve. Note: a string of comma-
+        *                                                 separated IDs will NOT work.
+        *     @type int          $post_parent             Page ID to retrieve child pages for. Use 0 to only retrieve
+        *                                                 top-level pages.
+        *     @type array        $post_parent__in         An array containing parent page IDs to query child pages from.
+        *     @type array        $post_parent__not_in     An array containing parent page IDs not to query child pages from.
+        *     @type string|array $post_type               A post type slug (string) or array of post type slugs.
+        *                                                 Default 'any' if using 'tax_query'.
+        *     @type string|array $post_status             A post status (string) or array of post statuses.
+        *     @type int          $posts_per_page          The number of posts to query for. Use -1 to request all posts.
+        *     @type int          $posts_per_archive_page  The number of posts to query for by archive page. Overrides
+        *                                                 'posts_per_page' when is_archive(), or is_search() are true.
+        *     @type string       $s                       Search keyword.
+        *     @type int          $second                  Second of the minute. Default empty. Accepts numbers 0-60.
+        *     @type array        $search_terms            Array of search terms.
+        *     @type bool         $sentence                Whether to search by phrase. Default false.
+        *     @type bool         $suppress_filters        Whether to suppress filters. Default false.
+        *     @type string       $tag                     Tag slug. Comma-separated (either), Plus-separated (all).
+        *     @type array        $tag__and                An array of tag ids (AND in).
+        *     @type array        $tag__in                 An array of tag ids (OR in).
+        *     @type array        $tag__not_in             An array of tag ids (NOT in).
+        *     @type int          $tag_id                  Tag id or comma-separated list of IDs.
+        *     @type array        $tag_slug__and           An array of tag slugs (AND in).
+        *     @type array        $tag_slug__in            An array of tag slugs (OR in). unless 'ignore_sticky_posts' is
+        *                                                 true. Note: a string of comma-separated IDs will NOT work.
+        *     @type array        $tax_query               An associative array of WP_Tax_Query arguments.
+        *                                                 {@see WP_Tax_Query->queries}
+        *     @type bool         $update_post_meta_cache  Whether to update the post meta cache. Default true.
+        *     @type bool         $update_post_term_cache  Whether to update the post term cache. Default true.
+        *     @type int          $w                       The week number of the year. Default empty. Accepts numbers 0-53.
+        *     @type int          $year                    The four-digit year. Default empty. Accepts any four-digit year.
+        * }
         */
-       function parse_query($query) {
-               if ( !empty($query) || !isset($this->query) ) {
+       public function parse_query( $query =  '' ) {
+               if ( ! empty( $query ) ) {
                        $this->init();
-                       if ( is_array($query) )
-                               $this->query_vars = $query;
-                       else
-                               parse_str($query, $this->query_vars);
-                       $this->query = $query;
+                       $this->query = $this->query_vars = wp_parse_args( $query );
+               } elseif ( ! isset( $this->query ) ) {
+                       $this->query = $this->query_vars;
                }
 
                $this->query_vars = $this->fill_query_vars($this->query_vars);
                $qv = &$this->query_vars;
+               $this->query_vars_changed = true;
 
                if ( ! empty($qv['robots']) )
                        $this->is_robots = true;
@@ -1265,16 +1562,22 @@ class WP_Query {
                $qv['monthnum'] = absint($qv['monthnum']);
                $qv['day'] = absint($qv['day']);
                $qv['w'] = absint($qv['w']);
-               $qv['m'] = absint($qv['m']);
+               $qv['m'] = preg_replace( '|[^0-9]|', '', $qv['m'] );
                $qv['paged'] = absint($qv['paged']);
                $qv['cat'] = preg_replace( '|[^0-9,-]|', '', $qv['cat'] ); // comma separated list of positive or negative integers
+               $qv['author'] = preg_replace( '|[^0-9,-]|', '', $qv['author'] ); // comma separated list of positive or negative integers
                $qv['pagename'] = trim( $qv['pagename'] );
                $qv['name'] = trim( $qv['name'] );
                if ( '' !== $qv['hour'] ) $qv['hour'] = absint($qv['hour']);
                if ( '' !== $qv['minute'] ) $qv['minute'] = absint($qv['minute']);
                if ( '' !== $qv['second'] ) $qv['second'] = absint($qv['second']);
+               if ( '' !== $qv['menu_order'] ) $qv['menu_order'] = absint($qv['menu_order']);
 
-               // Compat.  Map subpost to attachment.
+               // Fairly insane upper bound for search string lengths.
+               if ( ! empty( $qv['s'] ) && strlen( $qv['s'] ) > 1600 )
+                       $qv['s'] = '';
+
+               // Compat. Map subpost to attachment.
                if ( '' != $qv['subpost'] )
                        $qv['attachment'] = $qv['subpost'];
                if ( '' != $qv['subpost_id'] )
@@ -1296,10 +1599,12 @@ class WP_Query {
                } elseif ( '' != $qv['static'] || '' != $qv['pagename'] || !empty($qv['page_id']) ) {
                        $this->is_page = true;
                        $this->is_single = false;
-               } elseif ( !empty($qv['s']) ) {
-                       $this->is_search = true;
                } else {
-               // Look for archive queries.  Dates, categories, authors.
+                       // Look for archive queries. Dates, categories, authors, search, post type archives.
+
+                       if ( isset( $this->query['s'] ) ) {
+                               $this->is_search = true;
+                       }
 
                        if ( '' !== $qv['second'] ) {
                                $this->is_time = true;
@@ -1318,15 +1623,24 @@ class WP_Query {
 
                        if ( $qv['day'] ) {
                                if ( ! $this->is_date ) {
-                                       $this->is_day = true;
-                                       $this->is_date = true;
+                                       $date = sprintf( '%04d-%02d-%02d', $qv['year'], $qv['monthnum'], $qv['day'] );
+                                       if ( $qv['monthnum'] && $qv['year'] && ! wp_checkdate( $qv['monthnum'], $qv['day'], $qv['year'], $date ) ) {
+                                               $qv['error'] = '404';
+                                       } else {
+                                               $this->is_day = true;
+                                               $this->is_date = true;
+                                       }
                                }
                        }
 
                        if ( $qv['monthnum'] ) {
                                if ( ! $this->is_date ) {
-                                       $this->is_month = true;
-                                       $this->is_date = true;
+                                       if ( 12 < $qv['monthnum'] ) {
+                                               $qv['error'] = '404';
+                                       } else {
+                                               $this->is_month = true;
+                                               $this->is_date = true;
+                                       }
                                }
                        }
 
@@ -1354,120 +1668,55 @@ class WP_Query {
                                $this->is_date = true;
                        }
 
-                       if ( empty($qv['cat']) || ($qv['cat'] == '0') ) {
-                               $this->is_category = false;
-                       } else {
-                               if ( strpos($qv['cat'], '-') !== false ) {
-                                       $this->is_category = false;
-                               } else {
-                                       $this->is_category = true;
-                               }
-                       }
+                       $this->query_vars_hash = false;
+                       $this->parse_tax_query( $qv );
 
-                       if ( '' != $qv['category_name'] ) {
-                               $this->is_category = true;
+                       foreach ( $this->tax_query->queries as $tax_query ) {
+                               if ( 'NOT IN' != $tax_query['operator'] ) {
+                                       switch ( $tax_query['taxonomy'] ) {
+                                               case 'category':
+                                                       $this->is_category = true;
+                                                       break;
+                                               case 'post_tag':
+                                                       $this->is_tag = true;
+                                                       break;
+                                               default:
+                                                       $this->is_tax = true;
+                                       }
+                               }
                        }
+                       unset( $tax_query );
 
-                       if ( !is_array($qv['category__in']) || empty($qv['category__in']) ) {
-                               $qv['category__in'] = array();
+                       if ( empty($qv['author']) || ($qv['author'] == '0') ) {
+                               $this->is_author = false;
                        } else {
-                               $qv['category__in'] = array_map('absint', $qv['category__in']);
-                               $this->is_category = true;
+                               $this->is_author = true;
                        }
 
-                       if ( !is_array($qv['category__not_in']) || empty($qv['category__not_in']) ) {
-                               $qv['category__not_in'] = array();
-                       } else {
-                               $qv['category__not_in'] = array_map('absint', $qv['category__not_in']);
-                       }
+                       if ( '' != $qv['author_name'] )
+                               $this->is_author = true;
 
-                       if ( !is_array($qv['category__and']) || empty($qv['category__and']) ) {
-                               $qv['category__and'] = array();
-                       } else {
-                               $qv['category__and'] = array_map('absint', $qv['category__and']);
-                               $this->is_category = true;
+                       if ( !empty( $qv['post_type'] ) && ! is_array( $qv['post_type'] ) ) {
+                               $post_type_obj = get_post_type_object( $qv['post_type'] );
+                               if ( ! empty( $post_type_obj->has_archive ) )
+                                       $this->is_post_type_archive = true;
                        }
 
-                       if (  '' != $qv['tag'] )
-                               $this->is_tag = true;
+                       if ( $this->is_post_type_archive || $this->is_date || $this->is_author || $this->is_category || $this->is_tag || $this->is_tax )
+                               $this->is_archive = true;
+               }
 
-                       $qv['tag_id'] = absint($qv['tag_id']);
-                       if (  !empty($qv['tag_id']) )
-                               $this->is_tag = true;
+               if ( '' != $qv['feed'] )
+                       $this->is_feed = true;
 
-                       if ( !is_array($qv['tag__in']) || empty($qv['tag__in']) ) {
-                               $qv['tag__in'] = array();
-                       } else {
-                               $qv['tag__in'] = array_map('absint', $qv['tag__in']);
-                               $this->is_tag = true;
-                       }
+               if ( '' != $qv['tb'] )
+                       $this->is_trackback = true;
 
-                       if ( !is_array($qv['tag__not_in']) || empty($qv['tag__not_in']) ) {
-                               $qv['tag__not_in'] = array();
-                       } else {
-                               $qv['tag__not_in'] = array_map('absint', $qv['tag__not_in']);
-                       }
+               if ( '' != $qv['paged'] && ( intval($qv['paged']) > 1 ) )
+                       $this->is_paged = true;
 
-                       if ( !is_array($qv['tag__and']) || empty($qv['tag__and']) ) {
-                               $qv['tag__and'] = array();
-                       } else {
-                               $qv['tag__and'] = array_map('absint', $qv['tag__and']);
-                               $this->is_category = true;
-                       }
-
-                       if ( !is_array($qv['tag_slug__in']) || empty($qv['tag_slug__in']) ) {
-                               $qv['tag_slug__in'] = array();
-                       } else {
-                               $qv['tag_slug__in'] = array_map('sanitize_title', $qv['tag_slug__in']);
-                               $this->is_tag = true;
-                       }
-
-                       if ( !is_array($qv['tag_slug__and']) || empty($qv['tag_slug__and']) ) {
-                               $qv['tag_slug__and'] = array();
-                       } else {
-                               $qv['tag_slug__and'] = array_map('sanitize_title', $qv['tag_slug__and']);
-                               $this->is_tag = true;
-                       }
-
-                       if ( empty($qv['taxonomy']) || empty($qv['term']) ) {
-                               $this->is_tax = false;
-                               foreach ( $GLOBALS['wp_taxonomies'] as $taxonomy => $t ) {
-                                       if ( $t->query_var && isset($qv[$t->query_var]) && '' != $qv[$t->query_var] ) {
-                                               $qv['taxonomy'] = $taxonomy;
-                                               $qv['term'] = $qv[$t->query_var];
-                                               $this->is_tax = true;
-                                               break;
-                                       }
-                               }
-                       } else {
-                               $this->is_tax = true;
-                       }
-
-                       if ( empty($qv['author']) || ($qv['author'] == '0') ) {
-                               $this->is_author = false;
-                       } else {
-                               $this->is_author = true;
-                       }
-
-                       if ( '' != $qv['author_name'] ) {
-                               $this->is_author = true;
-                       }
-
-                       if ( ($this->is_date || $this->is_author || $this->is_category || $this->is_tag || $this->is_tax) )
-                               $this->is_archive = true;
-               }
-
-               if ( '' != $qv['feed'] )
-                       $this->is_feed = true;
-
-               if ( '' != $qv['tb'] )
-                       $this->is_trackback = true;
-
-               if ( '' != $qv['paged'] && ( intval($qv['paged']) > 1 ) )
-                       $this->is_paged = true;
-
-               if ( '' != $qv['comments_popup'] )
-                       $this->is_comments_popup = true;
+               if ( '' != $qv['comments_popup'] )
+                       $this->is_comments_popup = true;
 
                // if we're previewing inside the write screen
                if ( '' != $qv['preview'] )
@@ -1491,7 +1740,10 @@ class WP_Query {
 
                // Correct is_* for page_on_front and page_for_posts
                if ( $this->is_home && 'page' == get_option('show_on_front') && get_option('page_on_front') ) {
-                       $_query = wp_parse_args($query);
+                       $_query = wp_parse_args($this->query);
+                       // pagename can be set and empty depending on matched rewrite rules. Ignore an empty pagename.
+                       if ( isset($_query['pagename']) && '' == $_query['pagename'] )
+                               unset($_query['pagename']);
                        if ( empty($_query) || !array_diff( array_keys($_query), array('preview', 'page', 'paged', 'cpage') ) ) {
                                $this->is_page = true;
                                $this->is_home = false;
@@ -1505,7 +1757,7 @@ class WP_Query {
                }
 
                if ( '' != $qv['pagename'] ) {
-                       $this->queried_object =& get_page_by_path($qv['pagename']);
+                       $this->queried_object = get_page_by_path($qv['pagename']);
                        if ( !empty($this->queried_object) )
                                $this->queried_object_id = (int) $this->queried_object->ID;
                        else
@@ -1528,13 +1780,17 @@ class WP_Query {
 
                if ( !empty($qv['post_type']) ) {
                        if ( is_array($qv['post_type']) )
-                               $qv['post_type'] = array_map('sanitize_user', $qv['post_type'], array(true));
+                               $qv['post_type'] = array_map('sanitize_key', $qv['post_type']);
                        else
-                               $qv['post_type'] = sanitize_user($qv['post_type'], true);
+                               $qv['post_type'] = sanitize_key($qv['post_type']);
                }
 
-               if ( !empty($qv['post_status']) )
-                       $qv['post_status'] = preg_replace('|[^a-z0-9_,-]|', '', $qv['post_status']);
+               if ( ! empty( $qv['post_status'] ) ) {
+                       if ( is_array( $qv['post_status'] ) )
+                               $qv['post_status'] = array_map('sanitize_key', $qv['post_status']);
+                       else
+                               $qv['post_status'] = preg_replace('|[^a-z0-9_,-]|', '', $qv['post_status']);
+               }
 
                if ( $this->is_posts_page && ( ! isset($qv['withcomments']) || ! $qv['withcomments'] ) )
                        $this->is_comment_feed = false;
@@ -1545,8 +1801,495 @@ class WP_Query {
                if ( '404' == $qv['error'] )
                        $this->set_404();
 
-               if ( !empty($query) )
-                       do_action_ref_array('parse_query', array(&$this));
+               $this->query_vars_hash = md5( serialize( $this->query_vars ) );
+               $this->query_vars_changed = false;
+
+               /**
+                * Fires after the main query vars have been parsed.
+                *
+                * @since 1.5.0
+                *
+                * @param WP_Query &$this The WP_Query instance (passed by reference).
+                */
+               do_action_ref_array( 'parse_query', array( &$this ) );
+       }
+
+       /**
+        * Parses various taxonomy related query vars.
+        *
+        * For BC, this method is not marked as protected. See [28987].
+        *
+        * @access protected
+        * @since 3.1.0
+        *
+        * @param array &$q The query variables
+        */
+       function parse_tax_query( &$q ) {
+               if ( ! empty( $q['tax_query'] ) && is_array( $q['tax_query'] ) ) {
+                       $tax_query = $q['tax_query'];
+               } else {
+                       $tax_query = array();
+               }
+
+               if ( !empty($q['taxonomy']) && !empty($q['term']) ) {
+                       $tax_query[] = array(
+                               'taxonomy' => $q['taxonomy'],
+                               'terms' => array( $q['term'] ),
+                               'field' => 'slug',
+                       );
+               }
+
+               foreach ( get_taxonomies( array() , 'objects' ) as $taxonomy => $t ) {
+                       if ( 'post_tag' == $taxonomy )
+                               continue;       // Handled further down in the $q['tag'] block
+
+                       if ( $t->query_var && !empty( $q[$t->query_var] ) ) {
+                               $tax_query_defaults = array(
+                                       'taxonomy' => $taxonomy,
+                                       'field' => 'slug',
+                               );
+
+                               if ( isset( $t->rewrite['hierarchical'] ) && $t->rewrite['hierarchical'] ) {
+                                       $q[$t->query_var] = wp_basename( $q[$t->query_var] );
+                               }
+
+                               $term = $q[$t->query_var];
+
+                               if ( strpos($term, '+') !== false ) {
+                                       $terms = preg_split( '/[+]+/', $term );
+                                       foreach ( $terms as $term ) {
+                                               $tax_query[] = array_merge( $tax_query_defaults, array(
+                                                       'terms' => array( $term )
+                                               ) );
+                                       }
+                               } else {
+                                       $tax_query[] = array_merge( $tax_query_defaults, array(
+                                               'terms' => preg_split( '/[,]+/', $term )
+                                       ) );
+                               }
+                       }
+               }
+
+               // Category stuff
+               if ( ! empty( $q['cat'] ) && ! $this->is_singular ) {
+                       $cat_in = $cat_not_in = array();
+
+                       $cat_array = preg_split( '/[,\s]+/', urldecode( $q['cat'] ) );
+                       $cat_array = array_map( 'intval', $cat_array );
+                       $q['cat'] = implode( ',', $cat_array );
+
+                       foreach ( $cat_array as $cat ) {
+                               if ( $cat > 0 )
+                                       $cat_in[] = $cat;
+                               elseif ( $cat < 0 )
+                                       $cat_not_in[] = abs( $cat );
+                       }
+
+                       if ( ! empty( $cat_in ) ) {
+                               $tax_query[] = array(
+                                       'taxonomy' => 'category',
+                                       'terms' => $cat_in,
+                                       'field' => 'term_id',
+                                       'include_children' => true
+                               );
+                       }
+
+                       if ( ! empty( $cat_not_in ) ) {
+                               $tax_query[] = array(
+                                       'taxonomy' => 'category',
+                                       'terms' => $cat_not_in,
+                                       'field' => 'term_id',
+                                       'operator' => 'NOT IN',
+                                       'include_children' => true
+                               );
+                       }
+                       unset( $cat_array, $cat_in, $cat_not_in );
+               }
+
+               if ( ! empty( $q['category__and'] ) && 1 === count( (array) $q['category__and'] ) ) {
+                       $q['category__and'] = (array) $q['category__and'];
+                       if ( ! isset( $q['category__in'] ) )
+                               $q['category__in'] = array();
+                       $q['category__in'][] = absint( reset( $q['category__and'] ) );
+                       unset( $q['category__and'] );
+               }
+
+               if ( ! empty( $q['category__in'] ) ) {
+                       $q['category__in'] = array_map( 'absint', array_unique( (array) $q['category__in'] ) );
+                       $tax_query[] = array(
+                               'taxonomy' => 'category',
+                               'terms' => $q['category__in'],
+                               'field' => 'term_id',
+                               'include_children' => false
+                       );
+               }
+
+               if ( ! empty($q['category__not_in']) ) {
+                       $q['category__not_in'] = array_map( 'absint', array_unique( (array) $q['category__not_in'] ) );
+                       $tax_query[] = array(
+                               'taxonomy' => 'category',
+                               'terms' => $q['category__not_in'],
+                               'operator' => 'NOT IN',
+                               'include_children' => false
+                       );
+               }
+
+               if ( ! empty($q['category__and']) ) {
+                       $q['category__and'] = array_map( 'absint', array_unique( (array) $q['category__and'] ) );
+                       $tax_query[] = array(
+                               'taxonomy' => 'category',
+                               'terms' => $q['category__and'],
+                               'field' => 'term_id',
+                               'operator' => 'AND',
+                               'include_children' => false
+                       );
+               }
+
+               // Tag stuff
+               if ( '' != $q['tag'] && !$this->is_singular && $this->query_vars_changed ) {
+                       if ( strpos($q['tag'], ',') !== false ) {
+                               $tags = preg_split('/[,\r\n\t ]+/', $q['tag']);
+                               foreach ( (array) $tags as $tag ) {
+                                       $tag = sanitize_term_field('slug', $tag, 0, 'post_tag', 'db');
+                                       $q['tag_slug__in'][] = $tag;
+                               }
+                       } else if ( preg_match('/[+\r\n\t ]+/', $q['tag']) || !empty($q['cat']) ) {
+                               $tags = preg_split('/[+\r\n\t ]+/', $q['tag']);
+                               foreach ( (array) $tags as $tag ) {
+                                       $tag = sanitize_term_field('slug', $tag, 0, 'post_tag', 'db');
+                                       $q['tag_slug__and'][] = $tag;
+                               }
+                       } else {
+                               $q['tag'] = sanitize_term_field('slug', $q['tag'], 0, 'post_tag', 'db');
+                               $q['tag_slug__in'][] = $q['tag'];
+                       }
+               }
+
+               if ( !empty($q['tag_id']) ) {
+                       $q['tag_id'] = absint( $q['tag_id'] );
+                       $tax_query[] = array(
+                               'taxonomy' => 'post_tag',
+                               'terms' => $q['tag_id']
+                       );
+               }
+
+               if ( !empty($q['tag__in']) ) {
+                       $q['tag__in'] = array_map('absint', array_unique( (array) $q['tag__in'] ) );
+                       $tax_query[] = array(
+                               'taxonomy' => 'post_tag',
+                               'terms' => $q['tag__in']
+                       );
+               }
+
+               if ( !empty($q['tag__not_in']) ) {
+                       $q['tag__not_in'] = array_map('absint', array_unique( (array) $q['tag__not_in'] ) );
+                       $tax_query[] = array(
+                               'taxonomy' => 'post_tag',
+                               'terms' => $q['tag__not_in'],
+                               'operator' => 'NOT IN'
+                       );
+               }
+
+               if ( !empty($q['tag__and']) ) {
+                       $q['tag__and'] = array_map('absint', array_unique( (array) $q['tag__and'] ) );
+                       $tax_query[] = array(
+                               'taxonomy' => 'post_tag',
+                               'terms' => $q['tag__and'],
+                               'operator' => 'AND'
+                       );
+               }
+
+               if ( !empty($q['tag_slug__in']) ) {
+                       $q['tag_slug__in'] = array_map('sanitize_title_for_query', array_unique( (array) $q['tag_slug__in'] ) );
+                       $tax_query[] = array(
+                               'taxonomy' => 'post_tag',
+                               'terms' => $q['tag_slug__in'],
+                               'field' => 'slug'
+                       );
+               }
+
+               if ( !empty($q['tag_slug__and']) ) {
+                       $q['tag_slug__and'] = array_map('sanitize_title_for_query', array_unique( (array) $q['tag_slug__and'] ) );
+                       $tax_query[] = array(
+                               'taxonomy' => 'post_tag',
+                               'terms' => $q['tag_slug__and'],
+                               'field' => 'slug',
+                               'operator' => 'AND'
+                       );
+               }
+
+               $this->tax_query = new WP_Tax_Query( $tax_query );
+
+               /**
+                * Fires after taxonomy-related query vars have been parsed.
+                *
+                * @since 3.7.0
+                *
+                * @param WP_Query $this The WP_Query instance.
+                */
+               do_action( 'parse_tax_query', $this );
+       }
+
+       /**
+        * Generate SQL for the WHERE clause based on passed search terms.
+        *
+        * @since 3.7.0
+        *
+        * @global wpdb $wpdb
+        * @param array $q Query variables.
+        * @return string WHERE clause.
+        */
+       protected function parse_search( &$q ) {
+               global $wpdb;
+
+               $search = '';
+
+               // added slashes screw with quote grouping when done early, so done later
+               $q['s'] = stripslashes( $q['s'] );
+               if ( empty( $_GET['s'] ) && $this->is_main_query() )
+                       $q['s'] = urldecode( $q['s'] );
+               // there are no line breaks in <input /> fields
+               $q['s'] = str_replace( array( "\r", "\n" ), '', $q['s'] );
+               $q['search_terms_count'] = 1;
+               if ( ! empty( $q['sentence'] ) ) {
+                       $q['search_terms'] = array( $q['s'] );
+               } else {
+                       if ( preg_match_all( '/".*?("|$)|((?<=[\t ",+])|^)[^\t ",+]+/', $q['s'], $matches ) ) {
+                               $q['search_terms_count'] = count( $matches[0] );
+                               $q['search_terms'] = $this->parse_search_terms( $matches[0] );
+                               // if the search string has only short terms or stopwords, or is 10+ terms long, match it as sentence
+                               if ( empty( $q['search_terms'] ) || count( $q['search_terms'] ) > 9 )
+                                       $q['search_terms'] = array( $q['s'] );
+                       } else {
+                               $q['search_terms'] = array( $q['s'] );
+                       }
+               }
+
+               $n = ! empty( $q['exact'] ) ? '' : '%';
+               $searchand = '';
+               $q['search_orderby_title'] = array();
+               foreach ( $q['search_terms'] as $term ) {
+                       if ( $n ) {
+                               $like = '%' . $wpdb->esc_like( $term ) . '%';
+                               $q['search_orderby_title'][] = $wpdb->prepare( "$wpdb->posts.post_title LIKE %s", $like );
+                       }
+
+                       $like = $n . $wpdb->esc_like( $term ) . $n;
+                       $search .= $wpdb->prepare( "{$searchand}(($wpdb->posts.post_title LIKE %s) OR ($wpdb->posts.post_content LIKE %s))", $like, $like );
+                       $searchand = ' AND ';
+               }
+
+               if ( ! empty( $search ) ) {
+                       $search = " AND ({$search}) ";
+                       if ( ! is_user_logged_in() )
+                               $search .= " AND ($wpdb->posts.post_password = '') ";
+               }
+
+               return $search;
+       }
+
+       /**
+        * Check if the terms are suitable for searching.
+        *
+        * Uses an array of stopwords (terms) that are excluded from the separate
+        * term matching when searching for posts. The list of English stopwords is
+        * the approximate search engines list, and is translatable.
+        *
+        * @since 3.7.0
+        *
+        * @param array Terms to check.
+        * @return array Terms that are not stopwords.
+        */
+       protected function parse_search_terms( $terms ) {
+               $strtolower = function_exists( 'mb_strtolower' ) ? 'mb_strtolower' : 'strtolower';
+               $checked = array();
+
+               $stopwords = $this->get_search_stopwords();
+
+               foreach ( $terms as $term ) {
+                       // keep before/after spaces when term is for exact match
+                       if ( preg_match( '/^".+"$/', $term ) )
+                               $term = trim( $term, "\"'" );
+                       else
+                               $term = trim( $term, "\"' " );
+
+                       // Avoid single A-Z.
+                       if ( ! $term || ( 1 === strlen( $term ) && preg_match( '/^[a-z]$/i', $term ) ) )
+                               continue;
+
+                       if ( in_array( call_user_func( $strtolower, $term ), $stopwords, true ) )
+                               continue;
+
+                       $checked[] = $term;
+               }
+
+               return $checked;
+       }
+
+       /**
+        * Retrieve stopwords used when parsing search terms.
+        *
+        * @since 3.7.0
+        *
+        * @return array Stopwords.
+        */
+       protected function get_search_stopwords() {
+               if ( isset( $this->stopwords ) )
+                       return $this->stopwords;
+
+               /* translators: This is a comma-separated list of very common words that should be excluded from a search,
+                * like a, an, and the. These are usually called "stopwords". You should not simply translate these individual
+                * words into your language. Instead, look for and provide commonly accepted stopwords in your language.
+                */
+               $words = explode( ',', _x( 'about,an,are,as,at,be,by,com,for,from,how,in,is,it,of,on,or,that,the,this,to,was,what,when,where,who,will,with,www',
+                       'Comma-separated list of search stopwords in your language' ) );
+
+               $stopwords = array();
+               foreach( $words as $word ) {
+                       $word = trim( $word, "\r\n\t " );
+                       if ( $word )
+                               $stopwords[] = $word;
+               }
+
+               /**
+                * Filter stopwords used when parsing search terms.
+                *
+                * @since 3.7.0
+                *
+                * @param array $stopwords Stopwords.
+                */
+               $this->stopwords = apply_filters( 'wp_search_stopwords', $stopwords );
+               return $this->stopwords;
+       }
+
+       /**
+        * Generate SQL for the ORDER BY condition based on passed search terms.
+        *
+        * @global wpdb $wpdb
+        * @param array $q Query variables.
+        * @return string ORDER BY clause.
+        */
+       protected function parse_search_order( &$q ) {
+               global $wpdb;
+
+               if ( $q['search_terms_count'] > 1 ) {
+                       $num_terms = count( $q['search_orderby_title'] );
+                       $like = '%' . $wpdb->esc_like( $q['s'] ) . '%';
+
+                       $search_orderby = '(CASE ';
+                       // sentence match in 'post_title'
+                       $search_orderby .= $wpdb->prepare( "WHEN $wpdb->posts.post_title LIKE %s THEN 1 ", $like );
+
+                       // sanity limit, sort as sentence when more than 6 terms
+                       // (few searches are longer than 6 terms and most titles are not)
+                       if ( $num_terms < 7 ) {
+                               // all words in title
+                               $search_orderby .= 'WHEN ' . implode( ' AND ', $q['search_orderby_title'] ) . ' THEN 2 ';
+                               // any word in title, not needed when $num_terms == 1
+                               if ( $num_terms > 1 )
+                                       $search_orderby .= 'WHEN ' . implode( ' OR ', $q['search_orderby_title'] ) . ' THEN 3 ';
+                       }
+
+                       // sentence match in 'post_content'
+                       $search_orderby .= $wpdb->prepare( "WHEN $wpdb->posts.post_content LIKE %s THEN 4 ", $like );
+                       $search_orderby .= 'ELSE 5 END)';
+               } else {
+                       // single word or sentence search
+                       $search_orderby = reset( $q['search_orderby_title'] ) . ' DESC';
+               }
+
+               return $search_orderby;
+       }
+
+       /**
+        * If the passed orderby value is allowed, convert the alias to a
+        * properly-prefixed orderby value.
+        *
+        * @since 4.0.0
+        * @access protected
+        *
+        * @global wpdb $wpdb WordPress database access abstraction object.
+        *
+        * @param string $orderby Alias for the field to order by.
+        * @return string|bool Table-prefixed value to used in the ORDER clause. False otherwise.
+        */
+       protected function parse_orderby( $orderby ) {
+               global $wpdb;
+
+               // Used to filter values.
+               $allowed_keys = array(
+                       'post_name', 'post_author', 'post_date', 'post_title', 'post_modified',
+                       'post_parent', 'post_type', 'name', 'author', 'date', 'title', 'modified',
+                       'parent', 'type', 'ID', 'menu_order', 'comment_count', 'rand',
+               );
+
+               $meta_key = $this->get( 'meta_key' );
+               if ( ! empty( $meta_key ) ) {
+                       $allowed_keys[] = $meta_key;
+                       $allowed_keys[] = 'meta_value';
+                       $allowed_keys[] = 'meta_value_num';
+               }
+
+               if ( ! in_array( $orderby, $allowed_keys ) ) {
+                       return false;
+               }
+
+               switch ( $orderby ) {
+                       case 'post_name':
+                       case 'post_author':
+                       case 'post_date':
+                       case 'post_title':
+                       case 'post_modified':
+                       case 'post_parent':
+                       case 'post_type':
+                       case 'ID':
+                       case 'menu_order':
+                       case 'comment_count':
+                               $orderby = "$wpdb->posts.{$orderby}";
+                               break;
+                       case 'rand':
+                               $orderby = 'RAND()';
+                               break;
+                       case $meta_key:
+                       case 'meta_value':
+                               $type = $this->get( 'meta_type' );
+                               if ( ! empty( $type ) ) {
+                                       $meta_type = $this->meta_query->get_cast_for_type( $type );
+                                       $orderby = "CAST($wpdb->postmeta.meta_value AS {$meta_type})";
+                               } else {
+                                       $orderby = "$wpdb->postmeta.meta_value";
+                               }
+                               break;
+                       case 'meta_value_num':
+                               $orderby = "$wpdb->postmeta.meta_value+0";
+                               break;
+                       default:
+                               $orderby = "$wpdb->posts.post_" . $orderby;
+                               break;
+               }
+
+               return $orderby;
+       }
+
+       /**
+        * Parse an 'order' query variable and cast it to ASC or DESC as necessary.
+        *
+        * @since 4.0.0
+        * @access protected
+        *
+        * @param string $order The 'order' query variable.
+        * @return string The sanitized 'order' query variable.
+        */
+       protected function parse_order( $order ) {
+               if ( ! is_string( $order ) || empty( $order ) ) {
+                       return 'DESC';
+               }
+
+               if ( 'ASC' === strtoupper( $order ) ) {
+                       return 'ASC';
+               } else {
+                       return 'DESC';
+               }
        }
 
        /**
@@ -1555,7 +2298,7 @@ class WP_Query {
         * @since 2.0.0
         * @access public
         */
-       function set_404() {
+       public function set_404() {
                $is_feed = $this->is_feed;
 
                $this->init_query_flags();
@@ -1571,13 +2314,15 @@ class WP_Query {
         * @access public
         *
         * @param string $query_var Query variable key.
+        * @param mixed  $default   Value to return if the query variable is not set. Default ''.
         * @return mixed
         */
-       function get($query_var) {
-               if ( isset($this->query_vars[$query_var]) )
-                       return $this->query_vars[$query_var];
+       public function get( $query_var, $default = '' ) {
+               if ( isset( $this->query_vars[ $query_var ] ) ) {
+                       return $this->query_vars[ $query_var ];
+               }
 
-               return '';
+               return $default;
        }
 
        /**
@@ -1589,7 +2334,7 @@ class WP_Query {
         * @param string $query_var Query variable key.
         * @param mixed $value Query variable value.
         */
-       function set($query_var, $value) {
+       public function set($query_var, $value) {
                $this->query_vars[$query_var] = $value;
        }
 
@@ -1605,19 +2350,44 @@ class WP_Query {
         *
         * @return array List of posts.
         */
-       function &get_posts() {
-               global $wpdb, $user_ID, $_wp_using_ext_object_cache;
+       public function get_posts() {
+               global $wpdb;
 
-               do_action_ref_array('pre_get_posts', array(&$this));
+               $this->parse_query();
+
+               /**
+                * Fires after the query variable object is created, but before the actual query is run.
+                *
+                * Note: If using conditional tags, use the method versions within the passed instance
+                * (e.g. $this->is_main_query() instead of is_main_query()). This is because the functions
+                * like is_main_query() test against the global $wp_query instance, not the passed one.
+                *
+                * @since 2.0.0
+                *
+                * @param WP_Query &$this The WP_Query instance (passed by reference).
+                */
+               do_action_ref_array( 'pre_get_posts', array( &$this ) );
 
                // Shorthand.
                $q = &$this->query_vars;
 
+               // Fill again in case pre_get_posts unset some vars.
                $q = $this->fill_query_vars($q);
 
+               // Parse meta query
+               $this->meta_query = new WP_Meta_Query();
+               $this->meta_query->parse_query_vars( $q );
+
+               // Set a flag if a pre_get_posts hook changed the query vars.
+               $hash = md5( serialize( $this->query_vars ) );
+               if ( $hash != $this->query_vars_hash ) {
+                       $this->query_vars_changed = true;
+                       $this->query_vars_hash = $hash;
+               }
+               unset($hash);
+
                // First let's clear some variables
                $distinct = '';
-               $whichcat = '';
                $whichauthor = '';
                $whichmimetype = '';
                $where = '';
@@ -1625,18 +2395,23 @@ class WP_Query {
                $join = '';
                $search = '';
                $groupby = '';
-               $fields = "$wpdb->posts.*";
                $post_status_join = false;
                $page = 1;
 
-               if ( !isset($q['caller_get_posts']) )
-                       $q['caller_get_posts'] = false;
+               if ( isset( $q['caller_get_posts'] ) ) {
+                       _deprecated_argument( 'WP_Query', '3.1', __( '"caller_get_posts" is deprecated. Use "ignore_sticky_posts" instead.' ) );
+                       if ( !isset( $q['ignore_sticky_posts'] ) )
+                               $q['ignore_sticky_posts'] = $q['caller_get_posts'];
+               }
+
+               if ( !isset( $q['ignore_sticky_posts'] ) )
+                       $q['ignore_sticky_posts'] = false;
 
                if ( !isset($q['suppress_filters']) )
                        $q['suppress_filters'] = false;
 
                if ( !isset($q['cache_results']) ) {
-                       if ( $_wp_using_ext_object_cache )
+                       if ( wp_using_ext_object_cache() )
                                $q['cache_results'] = false;
                        else
                                $q['cache_results'] = true;
@@ -1655,8 +2430,9 @@ class WP_Query {
                                $q['post_type'] = '';
                }
                $post_type = $q['post_type'];
-               if ( !isset($q['posts_per_page']) || $q['posts_per_page'] == 0 )
-                       $q['posts_per_page'] = get_option('posts_per_page');
+               if ( empty( $q['posts_per_page'] ) ) {
+                       $q['posts_per_page'] = get_option( 'posts_per_page' );
+               }
                if ( isset($q['showposts']) && $q['showposts'] ) {
                        $q['showposts'] = (int) $q['showposts'];
                        $q['posts_per_page'] = $q['showposts'];
@@ -1670,8 +2446,14 @@ class WP_Query {
                                $q['nopaging'] = false;
                        }
                }
+
                if ( $this->is_feed ) {
-                       $q['posts_per_page'] = get_option('posts_per_rss');
+                       // This overrides posts_per_page.
+                       if ( ! empty( $q['posts_per_rss'] ) ) {
+                               $q['posts_per_page'] = $q['posts_per_rss'];
+                       } else {
+                               $q['posts_per_page'] = get_option( 'posts_per_rss' );
+                       }
                        $q['nopaging'] = false;
                }
                $q['posts_per_page'] = (int) $q['posts_per_page'];
@@ -1700,9 +2482,22 @@ class WP_Query {
                else
                        $q['no_found_rows'] = false;
 
-               // If a month is specified in the querystring, load that month
+               switch ( $q['fields'] ) {
+                       case 'ids':
+                               $fields = "$wpdb->posts.ID";
+                               break;
+                       case 'id=>parent':
+                               $fields = "$wpdb->posts.ID, $wpdb->posts.post_parent";
+                               break;
+                       default:
+                               $fields = "$wpdb->posts.*";
+               }
+
+               if ( '' !== $q['menu_order'] )
+                       $where .= " AND $wpdb->posts.menu_order = " . $q['menu_order'];
+
+               // The "m" parameter is meant for months but accepts datetimes of varying specificity
                if ( $q['m'] ) {
-                       $q['m'] = '' . preg_replace('|[^0-9]|', '', $q['m']);
                        $where .= " AND YEAR($wpdb->posts.post_date)=" . substr($q['m'], 0, 4);
                        if ( strlen($q['m']) > 5 )
                                $where .= " AND MONTH($wpdb->posts.post_date)=" . substr($q['m'], 4, 2);
@@ -1716,36 +2511,55 @@ class WP_Query {
                                $where .= " AND SECOND($wpdb->posts.post_date)=" . substr($q['m'], 12, 2);
                }
 
+               // Handle the other individual date parameters
+               $date_parameters = array();
+
                if ( '' !== $q['hour'] )
-                       $where .= " AND HOUR($wpdb->posts.post_date)='" . $q['hour'] . "'";
+                       $date_parameters['hour'] = $q['hour'];
 
                if ( '' !== $q['minute'] )
-                       $where .= " AND MINUTE($wpdb->posts.post_date)='" . $q['minute'] . "'";
+                       $date_parameters['minute'] = $q['minute'];
 
                if ( '' !== $q['second'] )
-                       $where .= " AND SECOND($wpdb->posts.post_date)='" . $q['second'] . "'";
+                       $date_parameters['second'] = $q['second'];
 
                if ( $q['year'] )
-                       $where .= " AND YEAR($wpdb->posts.post_date)='" . $q['year'] . "'";
+                       $date_parameters['year'] = $q['year'];
 
                if ( $q['monthnum'] )
-                       $where .= " AND MONTH($wpdb->posts.post_date)='" . $q['monthnum'] . "'";
+                       $date_parameters['monthnum'] = $q['monthnum'];
+
+               if ( $q['w'] )
+                       $date_parameters['week'] = $q['w'];
 
                if ( $q['day'] )
-                       $where .= " AND DAYOFMONTH($wpdb->posts.post_date)='" . $q['day'] . "'";
+                       $date_parameters['day'] = $q['day'];
+
+               if ( $date_parameters ) {
+                       $date_query = new WP_Date_Query( array( $date_parameters ) );
+                       $where .= $date_query->get_sql();
+               }
+               unset( $date_parameters, $date_query );
+
+               // Handle complex date queries
+               if ( ! empty( $q['date_query'] ) ) {
+                       $this->date_query = new WP_Date_Query( $q['date_query'] );
+                       $where .= $this->date_query->get_sql();
+               }
 
-               // If we've got a post_type AND its not "any" post_type.
+
+               // If we've got a post_type AND it's not "any" post_type.
                if ( !empty($q['post_type']) && 'any' != $q['post_type'] ) {
                        foreach ( (array)$q['post_type'] as $_post_type ) {
                                $ptype_obj = get_post_type_object($_post_type);
                                if ( !$ptype_obj || !$ptype_obj->query_var || empty($q[ $ptype_obj->query_var ]) )
                                        continue;
 
-                               if ( ! $ptype_obj->hierarchical || strpos($q[ $ptype_obj->query_var ], '/') === false ) {
-                                       // Non-hierarchical post_types & parent-level-hierarchical post_types can directly use 'name'
+                               if ( ! $ptype_obj->hierarchical ) {
+                                       // Non-hierarchical post types can directly use 'name'.
                                        $q['name'] = $q[ $ptype_obj->query_var ];
                                } else {
-                                       // Hierarchical post_types will operate through the
+                                       // Hierarchical post types will operate through 'pagename'.
                                        $q['pagename'] = $q[ $ptype_obj->query_var ];
                                        $q['name'] = '';
                                }
@@ -1757,7 +2571,7 @@ class WP_Query {
                }
 
                if ( '' != $q['name'] ) {
-                       $q['name'] = sanitize_title($q['name']);
+                       $q['name'] = sanitize_title_for_query( $q['name'] );
                        $where .= " AND $wpdb->posts.post_name = '" . $q['name'] . "'";
                } elseif ( '' != $q['pagename'] ) {
                        if ( isset($this->queried_object_id) ) {
@@ -1785,12 +2599,10 @@ class WP_Query {
 
                        $page_for_posts = get_option('page_for_posts');
                        if  ( ('page' != get_option('show_on_front') ) || empty($page_for_posts) || ( $reqpage != $page_for_posts ) ) {
-                               $q['pagename'] = str_replace('%2F', '/', urlencode(urldecode($q['pagename'])));
-                               $page_paths = '/' . trim($q['pagename'], '/');
-                               $q['pagename'] = sanitize_title(basename($page_paths));
+                               $q['pagename'] = sanitize_title_for_query( wp_basename( $q['pagename'] ) );
                                $q['name'] = $q['pagename'];
                                $where .= " AND ($wpdb->posts.ID = '$reqpage')";
-                               $reqpage_obj = get_page($reqpage);
+                               $reqpage_obj = get_post( $reqpage );
                                if ( is_object($reqpage_obj) && 'attachment' == $reqpage_obj->post_type ) {
                                        $this->is_attachment = true;
                                        $post_type = $q['post_type'] = 'attachment';
@@ -1799,20 +2611,16 @@ class WP_Query {
                                }
                        }
                } elseif ( '' != $q['attachment'] ) {
-                       $q['attachment'] = str_replace('%2F', '/', urlencode(urldecode($q['attachment'])));
-                       $attach_paths = '/' . trim($q['attachment'], '/');
-                       $q['attachment'] = sanitize_title(basename($attach_paths));
+                       $q['attachment'] = sanitize_title_for_query( wp_basename( $q['attachment'] ) );
                        $q['name'] = $q['attachment'];
                        $where .= " AND $wpdb->posts.post_name = '" . $q['attachment'] . "'";
                }
 
-               if ( $q['w'] )
-                       $where .= ' AND ' . _wp_mysql_week( "`$wpdb->posts`.`post_date`" ) . " = '" . $q['w'] . "'";
 
                if ( intval($q['comments_popup']) )
                        $q['p'] = absint($q['comments_popup']);
 
-               // If an attachment is requested by number, let it supercede any post number.
+               // If an attachment is requested by number, let it supersede any post number.
                if ( $q['attachment_id'] )
                        $q['p'] = absint($q['attachment_id']);
 
@@ -1827,8 +2635,15 @@ class WP_Query {
                        $where .= " AND {$wpdb->posts}.ID NOT IN ($post__not_in)";
                }
 
-               if ( is_numeric($q['post_parent']) )
+               if ( is_numeric( $q['post_parent'] ) ) {
                        $where .= $wpdb->prepare( " AND $wpdb->posts.post_parent = %d ", $q['post_parent'] );
+               } elseif ( $q['post_parent__in'] ) {
+                       $post_parent__in = implode( ',', array_map( 'absint', $q['post_parent__in'] ) );
+                       $where .= " AND {$wpdb->posts}.post_parent IN ($post_parent__in)";
+               } elseif ( $q['post_parent__not_in'] ) {
+                       $post_parent__not_in = implode( ',',  array_map( 'absint', $q['post_parent__not_in'] ) );
+                       $where .= " AND {$wpdb->posts}.post_parent NOT IN ($post_parent__not_in)";
+               }
 
                if ( $q['page_id'] ) {
                        if  ( ('page' != get_option('show_on_front') ) || ( $q['page_id'] != get_option('page_for_posts') ) ) {
@@ -1837,258 +2652,122 @@ class WP_Query {
                        }
                }
 
-               // If a search pattern is specified, load the posts that match
-               if ( !empty($q['s']) ) {
-                       // added slashes screw with quote grouping when done early, so done later
-                       $q['s'] = stripslashes($q['s']);
-                       if ( !empty($q['sentence']) ) {
-                               $q['search_terms'] = array($q['s']);
-                       } else {
-                               preg_match_all('/".*?("|$)|((?<=[\\s",+])|^)[^\\s",+]+/', $q['s'], $matches);
-                               $q['search_terms'] = array_map('_search_terms_tidy', $matches[0]);
-                       }
-                       $n = !empty($q['exact']) ? '' : '%';
-                       $searchand = '';
-                       foreach( (array) $q['search_terms'] as $term ) {
-                               $term = addslashes_gpc($term);
-                               $search .= "{$searchand}(($wpdb->posts.post_title LIKE '{$n}{$term}{$n}') OR ($wpdb->posts.post_content LIKE '{$n}{$term}{$n}'))";
-                               $searchand = ' AND ';
-                       }
-                       $term = esc_sql($q['s']);
-                       if ( empty($q['sentence']) && count($q['search_terms']) > 1 && $q['search_terms'][0] != $q['s'] )
-                               $search .= " OR ($wpdb->posts.post_title LIKE '{$n}{$term}{$n}') OR ($wpdb->posts.post_content LIKE '{$n}{$term}{$n}')";
-
-                       if ( !empty($search) ) {
-                               $search = " AND ({$search}) ";
-                               if ( !is_user_logged_in() )
-                                       $search .= " AND ($wpdb->posts.post_password = '') ";
-                       }
+               // If a search pattern is specified, load the posts that match.
+               if ( ! empty( $q['s'] ) ) {
+                       $search = $this->parse_search( $q );
                }
 
-               // Allow plugins to contextually add/remove/modify the search section of the database query
-               $search = apply_filters_ref_array('posts_search', array( $search, &$this ) );
+               /**
+                * Filter the search SQL that is used in the WHERE clause of WP_Query.
+                *
+                * @since 3.0.0
+                *
+                * @param string   $search Search SQL for WHERE clause.
+                * @param WP_Query $this   The current WP_Query object.
+                */
+               $search = apply_filters_ref_array( 'posts_search', array( $search, &$this ) );
 
-               // Category stuff
+               // Taxonomies
+               if ( !$this->is_singular ) {
+                       $this->parse_tax_query( $q );
 
-               if ( empty($q['cat']) || ($q['cat'] == '0') ||
-                               // Bypass cat checks if fetching specific posts
-                               $this->is_singular ) {
-                       $whichcat = '';
-               } else {
-                       $q['cat'] = ''.urldecode($q['cat']).'';
-                       $q['cat'] = addslashes_gpc($q['cat']);
-                       $cat_array = preg_split('/[,\s]+/', $q['cat']);
-                       $q['cat'] = '';
-                       $req_cats = array();
-                       foreach ( (array) $cat_array as $cat ) {
-                               $cat = intval($cat);
-                               $req_cats[] = $cat;
-                               $in = ($cat > 0);
-                               $cat = abs($cat);
-                               if ( $in ) {
-                                       $q['category__in'][] = $cat;
-                                       $q['category__in'] = array_merge($q['category__in'], get_term_children($cat, 'category'));
-                               } else {
-                                       $q['category__not_in'][] = $cat;
-                                       $q['category__not_in'] = array_merge($q['category__not_in'], get_term_children($cat, 'category'));
-                               }
-                       }
-                       $q['cat'] = implode(',', $req_cats);
-               }
+                       $clauses = $this->tax_query->get_sql( $wpdb->posts, 'ID' );
 
-               if ( !empty($q['category__in']) ) {
-                       $join = " INNER JOIN $wpdb->term_relationships ON ($wpdb->posts.ID = $wpdb->term_relationships.object_id) INNER JOIN $wpdb->term_taxonomy ON ($wpdb->term_relationships.term_taxonomy_id = $wpdb->term_taxonomy.term_taxonomy_id) ";
-                       $whichcat .= " AND $wpdb->term_taxonomy.taxonomy = 'category' ";
-                       $include_cats = "'" . implode("', '", $q['category__in']) . "'";
-                       $whichcat .= " AND $wpdb->term_taxonomy.term_id IN ($include_cats) ";
+                       $join .= $clauses['join'];
+                       $where .= $clauses['where'];
                }
 
-               if ( !empty($q['category__not_in']) ) {
-                       $cat_string = "'" . implode("', '", $q['category__not_in']) . "'";
-                       $whichcat .= " AND $wpdb->posts.ID NOT IN ( SELECT tr.object_id FROM $wpdb->term_relationships AS tr INNER JOIN $wpdb->term_taxonomy AS tt ON tr.term_taxonomy_id = tt.term_taxonomy_id WHERE tt.taxonomy = 'category' AND tt.term_id IN ($cat_string) )";
+               if ( $this->is_tax ) {
+                       if ( empty($post_type) ) {
+                               // Do a fully inclusive search for currently registered post types of queried taxonomies
+                               $post_type = array();
+                               $taxonomies = wp_list_pluck( $this->tax_query->queries, 'taxonomy' );
+                               foreach ( get_post_types( array( 'exclude_from_search' => false ) ) as $pt ) {
+                                       $object_taxonomies = $pt === 'attachment' ? get_taxonomies_for_attachments() : get_object_taxonomies( $pt );
+                                       if ( array_intersect( $taxonomies, $object_taxonomies ) )
+                                               $post_type[] = $pt;
+                               }
+                               if ( ! $post_type )
+                                       $post_type = 'any';
+                               elseif ( count( $post_type ) == 1 )
+                                       $post_type = $post_type[0];
+
+                               $post_status_join = true;
+                       } elseif ( in_array('attachment', (array) $post_type) ) {
+                               $post_status_join = true;
+                       }
                }
 
-               // Category stuff for nice URLs
-               if ( '' != $q['category_name'] && !$this->is_singular ) {
-                       $q['category_name'] = implode('/', array_map('sanitize_title', explode('/', $q['category_name'])));
-                       $reqcat = get_category_by_path($q['category_name']);
-                       $q['category_name'] = str_replace('%2F', '/', urlencode(urldecode($q['category_name'])));
-                       $cat_paths = '/' . trim($q['category_name'], '/');
-                       $q['category_name'] = sanitize_title(basename($cat_paths));
-
-                       $cat_paths = '/' . trim(urldecode($q['category_name']), '/');
-                       $q['category_name'] = sanitize_title(basename($cat_paths));
-                       $cat_paths = explode('/', $cat_paths);
-                       $cat_path = '';
-                       foreach ( (array) $cat_paths as $pathdir )
-                               $cat_path .= ( $pathdir != '' ? '/' : '' ) . sanitize_title($pathdir);
+               // Back-compat
+               if ( !empty($this->tax_query->queries) ) {
+                       $tax_query_in_and = wp_list_filter( $this->tax_query->queries, array( 'operator' => 'NOT IN' ), 'NOT' );
+                       if ( !empty( $tax_query_in_and ) ) {
+                               if ( !isset( $q['taxonomy'] ) ) {
+                                       foreach ( $tax_query_in_and as $a_tax_query ) {
+                                               if ( !in_array( $a_tax_query['taxonomy'], array( 'category', 'post_tag' ) ) ) {
+                                                       $q['taxonomy'] = $a_tax_query['taxonomy'];
+                                                       if ( 'slug' == $a_tax_query['field'] )
+                                                               $q['term'] = $a_tax_query['terms'][0];
+                                                       else
+                                                               $q['term_id'] = $a_tax_query['terms'][0];
 
-                       //if we don't match the entire hierarchy fallback on just matching the nicename
-                       if ( empty($reqcat) )
-                               $reqcat = get_category_by_path($q['category_name'], false);
+                                                       break;
+                                               }
+                                       }
+                               }
 
-                       if ( !empty($reqcat) )
-                               $reqcat = $reqcat->term_id;
-                       else
-                               $reqcat = 0;
+                               $cat_query = wp_list_filter( $tax_query_in_and, array( 'taxonomy' => 'category' ) );
+                               if ( ! empty( $cat_query ) ) {
+                                       $cat_query = reset( $cat_query );
 
-                       $q['cat'] = $reqcat;
+                                       if ( ! empty( $cat_query['terms'][0] ) ) {
+                                               $the_cat = get_term_by( $cat_query['field'], $cat_query['terms'][0], 'category' );
+                                               if ( $the_cat ) {
+                                                       $this->set( 'cat', $the_cat->term_id );
+                                                       $this->set( 'category_name', $the_cat->slug );
+                                               }
+                                               unset( $the_cat );
+                                       }
+                               }
+                               unset( $cat_query );
 
-                       $join = " INNER JOIN $wpdb->term_relationships ON ($wpdb->posts.ID = $wpdb->term_relationships.object_id) INNER JOIN $wpdb->term_taxonomy ON ($wpdb->term_relationships.term_taxonomy_id = $wpdb->term_taxonomy.term_taxonomy_id) ";
-                       $whichcat = " AND $wpdb->term_taxonomy.taxonomy = 'category' ";
-                       $in_cats = array($q['cat']);
-                       $in_cats = array_merge($in_cats, get_term_children($q['cat'], 'category'));
-                       $in_cats = "'" . implode("', '", $in_cats) . "'";
-                       $whichcat .= "AND $wpdb->term_taxonomy.term_id IN ($in_cats)";
-                       $groupby = "{$wpdb->posts}.ID";
-               }
+                               $tag_query = wp_list_filter( $tax_query_in_and, array( 'taxonomy' => 'post_tag' ) );
+                               if ( ! empty( $tag_query ) ) {
+                                       $tag_query = reset( $tag_query );
 
-               // Tags
-               if ( '' != $q['tag'] ) {
-                       if ( strpos($q['tag'], ',') !== false ) {
-                               $tags = preg_split('/[,\s]+/', $q['tag']);
-                               foreach ( (array) $tags as $tag ) {
-                                       $tag = sanitize_term_field('slug', $tag, 0, 'post_tag', 'db');
-                                       $q['tag_slug__in'][] = $tag;
-                               }
-                       } else if ( preg_match('/[+\s]+/', $q['tag']) || !empty($q['cat']) ) {
-                               $tags = preg_split('/[+\s]+/', $q['tag']);
-                               foreach ( (array) $tags as $tag ) {
-                                       $tag = sanitize_term_field('slug', $tag, 0, 'post_tag', 'db');
-                                       $q['tag_slug__and'][] = $tag;
+                                       if ( ! empty( $tag_query['terms'][0] ) ) {
+                                               $the_tag = get_term_by( $tag_query['field'], $tag_query['terms'][0], 'post_tag' );
+                                               if ( $the_tag )
+                                                       $this->set( 'tag_id', $the_tag->term_id );
+                                               unset( $the_tag );
+                                       }
                                }
-                       } else {
-                               $q['tag'] = sanitize_term_field('slug', $q['tag'], 0, 'post_tag', 'db');
-                               $q['tag_slug__in'][] = $q['tag'];
+                               unset( $tag_query );
                        }
                }
 
-               if ( !empty($q['category__in']) || !empty($q['meta_key']) || !empty($q['tag__in']) || !empty($q['tag_slug__in']) ) {
+               if ( !empty( $this->tax_query->queries ) || !empty( $this->meta_query->queries ) ) {
                        $groupby = "{$wpdb->posts}.ID";
                }
 
-               if ( !empty($q['tag__in']) && empty($q['cat']) ) {
-                       $join = " INNER JOIN $wpdb->term_relationships ON ($wpdb->posts.ID = $wpdb->term_relationships.object_id) INNER JOIN $wpdb->term_taxonomy ON ($wpdb->term_relationships.term_taxonomy_id = $wpdb->term_taxonomy.term_taxonomy_id) ";
-                       $whichcat .= " AND $wpdb->term_taxonomy.taxonomy = 'post_tag' ";
-                       $include_tags = "'" . implode("', '", $q['tag__in']) . "'";
-                       $whichcat .= " AND $wpdb->term_taxonomy.term_id IN ($include_tags) ";
-                       $reqtag = term_exists( $q['tag__in'][0], 'post_tag' );
-                       if ( !empty($reqtag) )
-                               $q['tag_id'] = $reqtag['term_id'];
-               }
-
-               if ( !empty($q['tag_slug__in']) && empty($q['cat']) ) {
-                       $join = " INNER JOIN $wpdb->term_relationships ON ($wpdb->posts.ID = $wpdb->term_relationships.object_id) INNER JOIN $wpdb->term_taxonomy ON ($wpdb->term_relationships.term_taxonomy_id = $wpdb->term_taxonomy.term_taxonomy_id) INNER JOIN $wpdb->terms ON ($wpdb->term_taxonomy.term_id = $wpdb->terms.term_id) ";
-                       $whichcat .= " AND $wpdb->term_taxonomy.taxonomy = 'post_tag' ";
-                       $include_tags = "'" . implode("', '", $q['tag_slug__in']) . "'";
-                       $whichcat .= " AND $wpdb->terms.slug IN ($include_tags) ";
-                       $reqtag = get_term_by( 'slug', $q['tag_slug__in'][0], 'post_tag' );
-                       if ( !empty($reqtag) )
-                               $q['tag_id'] = $reqtag->term_id;
-               }
-
-               if ( !empty($q['tag__not_in']) ) {
-                       $tag_string = "'" . implode("', '", $q['tag__not_in']) . "'";
-                       $whichcat .= " AND $wpdb->posts.ID NOT IN ( SELECT tr.object_id FROM $wpdb->term_relationships AS tr INNER JOIN $wpdb->term_taxonomy AS tt ON tr.term_taxonomy_id = tt.term_taxonomy_id WHERE tt.taxonomy = 'post_tag' AND tt.term_id IN ($tag_string) )";
-               }
-
-               // Tag and slug intersections.
-               $intersections = array('category__and' => 'category', 'tag__and' => 'post_tag', 'tag_slug__and' => 'post_tag', 'tag__in' => 'post_tag', 'tag_slug__in' => 'post_tag');
-               $tagin = array('tag__in', 'tag_slug__in'); // These are used to make some exceptions below
-               foreach ( $intersections as $item => $taxonomy ) {
-                       if ( empty($q[$item]) ) continue;
-                       if ( in_array($item, $tagin) && empty($q['cat']) ) continue; // We should already have what we need if categories aren't being used
-
-                       if ( $item != 'category__and' ) {
-                               $reqtag = term_exists( $q[$item][0], 'post_tag' );
-                               if ( !empty($reqtag) )
-                                       $q['tag_id'] = $reqtag['term_id'];
-                       }
-
-                       if ( in_array( $item, array('tag_slug__and', 'tag_slug__in' ) ) )
-                               $taxonomy_field = 'slug';
-                       else
-                               $taxonomy_field = 'term_id';
-
-                       $q[$item] = array_unique($q[$item]);
-                       $tsql = "SELECT p.ID FROM $wpdb->posts p INNER JOIN $wpdb->term_relationships tr ON (p.ID = tr.object_id) INNER JOIN $wpdb->term_taxonomy tt ON (tr.term_taxonomy_id = tt.term_taxonomy_id) INNER JOIN $wpdb->terms t ON (tt.term_id = t.term_id)";
-                       $tsql .= " WHERE tt.taxonomy = '$taxonomy' AND t.$taxonomy_field IN ('" . implode("', '", $q[$item]) . "')";
-                       if ( !in_array($item, $tagin) ) { // This next line is only helpful if we are doing an and relationship
-                               $tsql .= " GROUP BY p.ID HAVING count(p.ID) = " . count($q[$item]);
-                       }
-                       $post_ids = $wpdb->get_col($tsql);
-
-                       if ( count($post_ids) )
-                               $whichcat .= " AND $wpdb->posts.ID IN (" . implode(', ', $post_ids) . ") ";
-                       else {
-                               $whichcat = " AND 0 = 1";
-                               break;
-                       }
-               }
-
-               // Taxonomies
-               if ( $this->is_tax ) {
-                       if ( '' != $q['taxonomy'] ) {
-                               $taxonomy = $q['taxonomy'];
-                               $tt[$taxonomy] = $q['term'];
-                       } else {
-                               foreach ( $GLOBALS['wp_taxonomies'] as $taxonomy => $t ) {
-                                       if ( $t->query_var && '' != $q[$t->query_var] ) {
-                                               $tt[$taxonomy] = $q[$t->query_var];
-                                               break;
-                                       }
-                               }
-                       }
-
-                       $terms = get_terms($taxonomy, array('slug' => $tt[$taxonomy], 'hide_empty' => !is_taxonomy_hierarchical($taxonomy)));
+               // Author/user stuff
 
-                       if ( is_wp_error($terms) || empty($terms) ) {
-                               $whichcat = " AND 0 ";
-                       } else {
-                               foreach ( $terms as $term ) {
-                                       $term_ids[] = $term->term_id;
-                                       if ( is_taxonomy_hierarchical($taxonomy) ) {
-                                               $children = get_term_children($term->term_id, $taxonomy);
-                                               $term_ids = array_merge($term_ids, $children);
-                                       }
-                               }
-                               $post_ids = get_objects_in_term($term_ids, $taxonomy);
-                               if ( !is_wp_error($post_ids) && !empty($post_ids) ) {
-                                       $whichcat .= " AND $wpdb->posts.ID IN (" . implode(', ', $post_ids) . ") ";
-                                       if ( empty($post_type) ) {
-                                               $post_type = 'any';
-                                               $post_status_join = true;
-                                       } elseif ( in_array('attachment', (array)$post_type) ) {
-                                               $post_status_join = true;
-                                       }
-                               } else {
-                                       $whichcat = " AND 0 ";
-                               }
+               if ( ! empty( $q['author'] ) && $q['author'] != '0' ) {
+                       $q['author'] = addslashes_gpc( '' . urldecode( $q['author'] ) );
+                       $authors = array_unique( array_map( 'intval', preg_split( '/[,\s]+/', $q['author'] ) ) );
+                       foreach ( $authors as $author ) {
+                               $key = $author > 0 ? 'author__in' : 'author__not_in';
+                               $q[$key][] = abs( $author );
                        }
+                       $q['author'] = implode( ',', $authors );
                }
 
-               // Author/user stuff
-
-               if ( empty($q['author']) || ($q['author'] == '0') ) {
-                       $whichauthor = '';
-               } else {
-                       $q['author'] = (string)urldecode($q['author']);
-                       $q['author'] = addslashes_gpc($q['author']);
-                       if ( strpos($q['author'], '-') !== false ) {
-                               $eq = '!=';
-                               $andor = 'AND';
-                               $q['author'] = explode('-', $q['author']);
-                               $q['author'] = (string)absint($q['author'][1]);
-                       } else {
-                               $eq = '=';
-                               $andor = 'OR';
-                       }
-                       $author_array = preg_split('/[,\s]+/', $q['author']);
-                       $_author_array = array();
-                       foreach ( $author_array as $key => $_author )
-                               $_author_array[] = "$wpdb->posts.post_author " . $eq . ' ' . absint($_author);
-                       $whichauthor .= ' AND (' . implode(" $andor ", $_author_array) . ')';
-                       unset($author_array, $_author_array);
+               if ( ! empty( $q['author__not_in'] ) ) {
+                       $author__not_in = implode( ',', array_map( 'absint', array_unique( (array) $q['author__not_in'] ) ) );
+                       $where .= " AND {$wpdb->posts}.post_author NOT IN ($author__not_in) ";
+               } elseif ( ! empty( $q['author__in'] ) ) {
+                       $author__in = implode( ',', array_map( 'absint', array_unique( (array) $q['author__in'] ) ) );
+                       $where .= " AND {$wpdb->posts}.post_author IN ($author__in) ";
                }
 
                // Author stuff for nice URLs
@@ -2099,10 +2778,10 @@ class WP_Query {
                                if ( $q['author_name'][ count($q['author_name'])-1 ] ) {
                                        $q['author_name'] = $q['author_name'][count($q['author_name'])-1]; // no trailing slash
                                } else {
-                                       $q['author_name'] = $q['author_name'][count($q['author_name'])-2]; // there was a trailling slash
+                                       $q['author_name'] = $q['author_name'][count($q['author_name'])-2]; // there was a trailing slash
                                }
                        }
-                       $q['author_name'] = sanitize_title($q['author_name']);
+                       $q['author_name'] = sanitize_title_for_query( $q['author_name'] );
                        $q['author'] = get_user_by('slug', $q['author_name']);
                        if ( $q['author'] )
                                $q['author'] = $q['author']->ID;
@@ -2111,90 +2790,116 @@ class WP_Query {
 
                // MIME-Type stuff for attachment browsing
 
-               if ( isset($q['post_mime_type']) && '' != $q['post_mime_type'] ) {
-                       $table_alias = $post_status_join ? $wpdb->posts : '';
-                       $whichmimetype = wp_post_mime_type_where($q['post_mime_type'], $table_alias);
-               }
+               if ( isset( $q['post_mime_type'] ) && '' != $q['post_mime_type'] )
+                       $whichmimetype = wp_post_mime_type_where( $q['post_mime_type'], $wpdb->posts );
 
-               $where .= $search . $whichcat . $whichauthor . $whichmimetype;
+               $where .= $search . $whichauthor . $whichmimetype;
 
-               if ( empty($q['order']) || ((strtoupper($q['order']) != 'ASC') && (strtoupper($q['order']) != 'DESC')) )
+               if ( ! isset( $q['order'] ) ) {
                        $q['order'] = 'DESC';
+               } else {
+                       $q['order'] = $this->parse_order( $q['order'] );
+               }
 
-               // Order by
-               if ( empty($q['orderby']) ) {
-                       $q['orderby'] = "$wpdb->posts.post_date " . $q['order'];
+               // Order by.
+               if ( empty( $q['orderby'] ) ) {
+                       /*
+                        * Boolean false or empty array blanks out ORDER BY,
+                        * while leaving the value unset or otherwise empty sets the default.
+                        */
+                       if ( isset( $q['orderby'] ) && ( is_array( $q['orderby'] ) || false === $q['orderby'] ) ) {
+                               $orderby = '';
+                       } else {
+                               $orderby = "$wpdb->posts.post_date " . $q['order'];
+                       }
                } elseif ( 'none' == $q['orderby'] ) {
-                       $q['orderby'] = '';
+                       $orderby = '';
+               } elseif ( $q['orderby'] == 'post__in' && ! empty( $post__in ) ) {
+                       $orderby = "FIELD( {$wpdb->posts}.ID, $post__in )";
+               } elseif ( $q['orderby'] == 'post_parent__in' && ! empty( $post_parent__in ) ) {
+                       $orderby = "FIELD( {$wpdb->posts}.post_parent, $post_parent__in )";
                } else {
-                       // Used to filter values
-                       $allowed_keys = array('author', 'date', 'title', 'modified', 'menu_order', 'parent', 'ID', 'rand', 'comment_count');
-                       if ( !empty($q['meta_key']) ) {
-                               $allowed_keys[] = $q['meta_key'];
-                               $allowed_keys[] = 'meta_value';
-                               $allowed_keys[] = 'meta_value_num';
-                       }
-                       $q['orderby'] = urldecode($q['orderby']);
-                       $q['orderby'] = addslashes_gpc($q['orderby']);
-                       $orderby_array = explode(' ', $q['orderby']);
-                       $q['orderby'] = '';
-
-                       foreach ( $orderby_array as $i => $orderby ) {
-                               // Only allow certain values for safety
-                               if ( ! in_array($orderby, $allowed_keys) )
-                                       continue;
+                       $orderby_array = array();
+                       if ( is_array( $q['orderby'] ) ) {
+                               foreach ( $q['orderby'] as $_orderby => $order ) {
+                                       $orderby = addslashes_gpc( urldecode( $_orderby ) );
+                                       $parsed  = $this->parse_orderby( $orderby );
 
-                               switch ( $orderby ) {
-                                       case 'menu_order':
-                                               break;
-                                       case 'ID':
-                                               $orderby = "$wpdb->posts.ID";
-                                               break;
-                                       case 'rand':
-                                               $orderby = 'RAND()';
-                                               break;
-                                       case $q['meta_key']:
-                                       case 'meta_value':
-                                               $orderby = "$wpdb->postmeta.meta_value";
-                                               break;
-                                       case 'meta_value_num':
-                                               $orderby = "$wpdb->postmeta.meta_value+0";
-                                               break;
-                                       case 'comment_count':
-                                               $orderby = "$wpdb->posts.comment_count";
-                                               break;
-                                       default:
-                                               $orderby = "$wpdb->posts.post_" . $orderby;
+                                       if ( ! $parsed ) {
+                                               continue;
+                                       }
+
+                                       $orderby_array[] = $parsed . ' ' . $this->parse_order( $order );
                                }
+                               $orderby = implode( ', ', $orderby_array );
 
-                               $q['orderby'] .= (($i == 0) ? '' : ',') . $orderby;
-                       }
+                       } else {
+                               $q['orderby'] = urldecode( $q['orderby'] );
+                               $q['orderby'] = addslashes_gpc( $q['orderby'] );
 
-                       // append ASC or DESC at the end
-                       if ( !empty($q['orderby']))
-                               $q['orderby'] .= " {$q['order']}";
+                               foreach ( explode( ' ', $q['orderby'] ) as $i => $orderby ) {
+                                       $parsed = $this->parse_orderby( $orderby );
+                                       // Only allow certain values for safety.
+                                       if ( ! $parsed ) {
+                                               continue;
+                                       }
+
+                                       $orderby_array[] = $parsed;
+                               }
+                               $orderby = implode( ' ' . $q['order'] . ', ', $orderby_array );
+
+                               if ( empty( $orderby ) ) {
+                                       $orderby = "$wpdb->posts.post_date ".$q['order'];
+                               } else {
+                                       $orderby .= " {$q['order']}";
+                               }
+                       }
+               }
 
-                       if ( empty($q['orderby']) )
-                               $q['orderby'] = "$wpdb->posts.post_date ".$q['order'];
+               // Order search results by relevance only when another "orderby" is not specified in the query.
+               if ( ! empty( $q['s'] ) ) {
+                       $search_orderby = '';
+                       if ( ! empty( $q['search_orderby_title'] ) && ( empty( $q['orderby'] ) && ! $this->is_feed ) || ( isset( $q['orderby'] ) && 'relevance' === $q['orderby'] ) )
+                               $search_orderby = $this->parse_search_order( $q );
+
+                       /**
+                        * Filter the ORDER BY used when ordering search results.
+                        *
+                        * @since 3.7.0
+                        *
+                        * @param string   $search_orderby The ORDER BY clause.
+                        * @param WP_Query $this           The current WP_Query instance.
+                        */
+                       $search_orderby = apply_filters( 'posts_search_orderby', $search_orderby, $this );
+                       if ( $search_orderby )
+                               $orderby = $orderby ? $search_orderby . ', ' . $orderby : $search_orderby;
                }
 
-               if ( is_array($post_type) ) {
+               if ( is_array( $post_type ) && count( $post_type ) > 1 ) {
                        $post_type_cap = 'multiple_post_type';
                } else {
-                       $post_type_object = get_post_type_object ( $post_type );
-                       if ( !empty($post_type_object) )
-                               $post_type_cap = $post_type_object->capability_type;
-                       else
+                       if ( is_array( $post_type ) )
+                               $post_type = reset( $post_type );
+                       $post_type_object = get_post_type_object( $post_type );
+                       if ( empty( $post_type_object ) )
                                $post_type_cap = $post_type;
                }
 
-               $exclude_post_types = '';
-               $in_search_post_types = get_post_types( array('exclude_from_search' => false) );
-               if ( ! empty( $in_search_post_types ) )
-                       $exclude_post_types .= $wpdb->prepare(" AND $wpdb->posts.post_type IN ('" . join("', '", $in_search_post_types ) . "')");
+               if ( isset( $q['post_password'] ) ) {
+                       $where .= $wpdb->prepare( " AND $wpdb->posts.post_password = %s", $q['post_password'] );
+                       if ( empty( $q['perm'] ) ) {
+                               $q['perm'] = 'readable';
+                       }
+               } elseif ( isset( $q['has_password'] ) ) {
+                       $where .= sprintf( " AND $wpdb->posts.post_password %s ''", $q['has_password'] ? '!=' : '=' );
+               }
 
                if ( 'any' == $post_type ) {
-                       $where .= $exclude_post_types;
+                       $in_search_post_types = get_post_types( array('exclude_from_search' => false) );
+                       if ( empty( $in_search_post_types ) )
+                               $where .= ' AND 1=0 ';
+                       else
+                               $where .= " AND $wpdb->posts.post_type IN ('" . join("', '", $in_search_post_types ) . "')";
                } elseif ( !empty( $post_type ) && is_array( $post_type ) ) {
                        $where .= " AND $wpdb->posts.post_type IN ('" . join("', '", $post_type) . "')";
                } elseif ( ! empty( $post_type ) ) {
@@ -2211,28 +2916,33 @@ class WP_Query {
                        $post_type_object = get_post_type_object ( 'post' );
                }
 
-               if ( !empty($post_type_object) ) {
-                       $post_type_cap = $post_type_object->capability_type;
-                       $edit_cap = $post_type_object->cap->edit_post;
-                       $read_cap = $post_type_object->cap->read_post;
+               $edit_cap = 'edit_post';
+               $read_cap = 'read_post';
+
+               if ( ! empty( $post_type_object ) ) {
                        $edit_others_cap = $post_type_object->cap->edit_others_posts;
                        $read_private_cap = $post_type_object->cap->read_private_posts;
                } else {
-                       $edit_cap = 'edit_' . $post_type_cap;
-                       $read_cap = 'read_' . $post_type_cap;
                        $edit_others_cap = 'edit_others_' . $post_type_cap . 's';
                        $read_private_cap = 'read_private_' . $post_type_cap . 's';
                }
 
-               if ( isset($q['post_status']) && '' != $q['post_status'] ) {
+               $user_id = get_current_user_id();
+
+               if ( ! empty( $q['post_status'] ) ) {
                        $statuswheres = array();
-                       $q_status = explode(',', $q['post_status']);
+                       $q_status = $q['post_status'];
+                       if ( ! is_array( $q_status ) )
+                               $q_status = explode(',', $q_status);
                        $r_status = array();
                        $p_status = array();
                        $e_status = array();
-                       if ( $q['post_status'] == 'any' ) {
-                               foreach ( get_post_stati( array('exclude_from_search' => true) ) as $status )
-                                       $e_status[] = "$wpdb->posts.post_status <> '$status'";
+                       if ( in_array( 'any', $q_status ) ) {
+                               foreach ( get_post_stati( array( 'exclude_from_search' => true ) ) as $status ) {
+                                       if ( ! in_array( $status, $q_status ) ) {
+                                               $e_status[] = "$wpdb->posts.post_status <> '$status'";
+                                       }
+                               }
                        } else {
                                foreach ( get_post_stati() as $status ) {
                                        if ( in_array( $status, $q_status ) ) {
@@ -2254,13 +2964,13 @@ class WP_Query {
                        }
                        if ( !empty($r_status) ) {
                                if ( !empty($q['perm'] ) && 'editable' == $q['perm'] && !current_user_can($edit_others_cap) )
-                                       $statuswheres[] = "($wpdb->posts.post_author = $user_ID " .  "AND (" . join( ' OR ', $r_status ) . "))";
+                                       $statuswheres[] = "($wpdb->posts.post_author = $user_id " . "AND (" . join( ' OR ', $r_status ) . "))";
                                else
                                        $statuswheres[] = "(" . join( ' OR ', $r_status ) . ")";
                        }
                        if ( !empty($p_status) ) {
                                if ( !empty($q['perm'] ) && 'readable' == $q['perm'] && !current_user_can($read_private_cap) )
-                                       $statuswheres[] = "($wpdb->posts.post_author = $user_ID " .  "AND (" . join( ' OR ', $p_status ) . "))";
+                                       $statuswheres[] = "($wpdb->posts.post_author = $user_id " . "AND (" . join( ' OR ', $p_status ) . "))";
                                else
                                        $statuswheres[] = "(" . join( ' OR ', $p_status ) . ")";
                        }
@@ -2269,8 +2979,10 @@ class WP_Query {
                                foreach ( $statuswheres as $index => $statuswhere )
                                        $statuswheres[$index] = "($statuswhere OR ($wpdb->posts.post_status = 'inherit' AND " . str_replace($wpdb->posts, 'p2', $statuswhere) . "))";
                        }
-                       foreach ( $statuswheres as $statuswhere )
-                               $where .= " AND $statuswhere";
+                       $where_status = implode( ' OR ', $statuswheres );
+                       if ( ! empty( $where_status ) ) {
+                               $where .= " AND ($where_status)";
+                       }
                } elseif ( !$this->is_singular ) {
                        $where .= " AND ($wpdb->posts.post_status = 'publish'";
 
@@ -2282,7 +2994,7 @@ class WP_Query {
                                $where .= " OR $wpdb->posts.post_status = '$state'";
                        }
 
-                       if ( is_admin() ) {
+                       if ( $this->is_admin ) {
                                // Add protected states that should show in the admin all list.
                                $admin_all_states = get_post_stati( array('protected' => true, 'show_in_admin_all_list' => true) );
                                foreach ( (array) $admin_all_states as $state )
@@ -2293,50 +3005,61 @@ class WP_Query {
                                // Add private states that are limited to viewing by the author of a post or someone who has caps to read private states.
                                $private_states = get_post_stati( array('private' => true) );
                                foreach ( (array) $private_states as $state )
-                                       $where .= current_user_can( $read_private_cap ) ? " OR $wpdb->posts.post_status = '$state'" : " OR $wpdb->posts.post_author = $user_ID AND $wpdb->posts.post_status = '$state'";
+                                       $where .= current_user_can( $read_private_cap ) ? " OR $wpdb->posts.post_status = '$state'" : " OR $wpdb->posts.post_author = $user_id AND $wpdb->posts.post_status = '$state'";
                        }
 
                        $where .= ')';
                }
 
-               // postmeta queries
-               if ( ! empty($q['meta_key']) || ! empty($q['meta_value']) )
-                       $join .= " JOIN $wpdb->postmeta ON ($wpdb->posts.ID = $wpdb->postmeta.post_id) ";
-               if ( ! empty($q['meta_key']) )
-                       $where .= $wpdb->prepare(" AND $wpdb->postmeta.meta_key = %s ", $q['meta_key']);
-               if ( ! empty($q['meta_value']) ) {
-                       if ( empty($q['meta_compare']) || ! in_array($q['meta_compare'], array('=', '!=', '>', '>=', '<', '<=')) )
-                               $q['meta_compare'] = '=';
-
-                       $where .= $wpdb->prepare("AND $wpdb->postmeta.meta_value {$q['meta_compare']} %s ", $q['meta_value']);
+               if ( !empty( $this->meta_query->queries ) ) {
+                       $clauses = $this->meta_query->get_sql( 'post', $wpdb->posts, 'ID', $this );
+                       $join .= $clauses['join'];
+                       $where .= $clauses['where'];
                }
 
-               // Apply filters on where and join prior to paging so that any
-               // manipulations to them are reflected in the paging by day queries.
+               /*
+                * Apply filters on where and join prior to paging so that any
+                * manipulations to them are reflected in the paging by day queries.
+                */
                if ( !$q['suppress_filters'] ) {
-                       $where = apply_filters_ref_array('posts_where', array( $where, &$this ) );
-                       $join = apply_filters_ref_array('posts_join', array( $join, &$this ) );
+                       /**
+                        * Filter the WHERE clause of the query.
+                        *
+                        * @since 1.5.0
+                        *
+                        * @param string   $where The WHERE clause of the query.
+                        * @param WP_Query &$this The WP_Query instance (passed by reference).
+                        */
+                       $where = apply_filters_ref_array( 'posts_where', array( $where, &$this ) );
+
+                       /**
+                        * Filter the JOIN clause of the query.
+                        *
+                        * @since 1.5.0
+                        *
+                        * @param string   $where The JOIN clause of the query.
+                        * @param WP_Query &$this The WP_Query instance (passed by reference).
+                        */
+                       $join = apply_filters_ref_array( 'posts_join', array( $join, &$this ) );
                }
 
                // Paging
                if ( empty($q['nopaging']) && !$this->is_singular ) {
                        $page = absint($q['paged']);
-                       if ( empty($page) )
+                       if ( !$page )
                                $page = 1;
 
                        if ( empty($q['offset']) ) {
-                               $pgstrt = '';
-                               $pgstrt = ($page - 1) * $q['posts_per_page'] . ', ';
-                               $limits = 'LIMIT ' . $pgstrt . $q['posts_per_page'];
+                               $pgstrt = absint( ( $page - 1 ) * $q['posts_per_page'] ) . ', ';
                        } else { // we're ignoring $page and using 'offset'
                                $q['offset'] = absint($q['offset']);
                                $pgstrt = $q['offset'] . ', ';
-                               $limits = 'LIMIT ' . $pgstrt . $q['posts_per_page'];
                        }
+                       $limits = 'LIMIT ' . $pgstrt . $q['posts_per_page'];
                }
 
                // Comments feeds
-               if ( $this->is_comment_feed && ( $this->is_archive || $this->is_search || !$this->is_singular ) ) {
+               if ( $this->is_comment_feed && ! $this->is_singular ) {
                        if ( $this->is_archive || $this->is_search ) {
                                $cjoin = "JOIN $wpdb->posts ON ($wpdb->comments.comment_post_ID = $wpdb->posts.ID) $join ";
                                $cwhere = "WHERE comment_approved = '1' $where";
@@ -2348,11 +3071,55 @@ class WP_Query {
                        }
 
                        if ( !$q['suppress_filters'] ) {
-                               $cjoin = apply_filters_ref_array('comment_feed_join', array( $cjoin, &$this ) );
-                               $cwhere = apply_filters_ref_array('comment_feed_where', array( $cwhere, &$this ) );
-                               $cgroupby = apply_filters_ref_array('comment_feed_groupby', array( $cgroupby, &$this ) );
-                               $corderby = apply_filters_ref_array('comment_feed_orderby', array( 'comment_date_gmt DESC', &$this ) );
-                               $climits = apply_filters_ref_array('comment_feed_limits', array( 'LIMIT ' . get_option('posts_per_rss'), &$this ) );
+                               /**
+                                * Filter the JOIN clause of the comments feed query before sending.
+                                *
+                                * @since 2.2.0
+                                *
+                                * @param string   $cjoin The JOIN clause of the query.
+                                * @param WP_Query &$this The WP_Query instance (passed by reference).
+                                */
+                               $cjoin = apply_filters_ref_array( 'comment_feed_join', array( $cjoin, &$this ) );
+
+                               /**
+                                * Filter the WHERE clause of the comments feed query before sending.
+                                *
+                                * @since 2.2.0
+                                *
+                                * @param string   $cwhere The WHERE clause of the query.
+                                * @param WP_Query &$this  The WP_Query instance (passed by reference).
+                                */
+                               $cwhere = apply_filters_ref_array( 'comment_feed_where', array( $cwhere, &$this ) );
+
+                               /**
+                                * Filter the GROUP BY clause of the comments feed query before sending.
+                                *
+                                * @since 2.2.0
+                                *
+                                * @param string   $cgroupby The GROUP BY clause of the query.
+                                * @param WP_Query &$this    The WP_Query instance (passed by reference).
+                                */
+                               $cgroupby = apply_filters_ref_array( 'comment_feed_groupby', array( $cgroupby, &$this ) );
+
+                               /**
+                                * Filter the ORDER BY clause of the comments feed query before sending.
+                                *
+                                * @since 2.8.0
+                                *
+                                * @param string   $corderby The ORDER BY clause of the query.
+                                * @param WP_Query &$this    The WP_Query instance (passed by reference).
+                                */
+                               $corderby = apply_filters_ref_array( 'comment_feed_orderby', array( 'comment_date_gmt DESC', &$this ) );
+
+                               /**
+                                * Filter the LIMIT clause of the comments feed query before sending.
+                                *
+                                * @since 2.8.0
+                                *
+                                * @param string   $climits The JOIN clause of the query.
+                                * @param WP_Query &$this   The WP_Query instance (passed by reference).
+                                */
+                               $climits = apply_filters_ref_array( 'comment_feed_limits', array( 'LIMIT ' . get_option('posts_per_rss'), &$this ) );
                        }
                        $cgroupby = ( ! empty( $cgroupby ) ) ? 'GROUP BY ' . $cgroupby : '';
                        $corderby = ( ! empty( $corderby ) ) ? 'ORDER BY ' . $corderby : '';
@@ -2373,71 +3140,360 @@ class WP_Query {
                                $where = "AND 0";
                }
 
-               $orderby = $q['orderby'];
+               $pieces = array( 'where', 'groupby', 'join', 'orderby', 'distinct', 'fields', 'limits' );
 
-               // Apply post-paging filters on where and join.  Only plugins that
-               // manipulate paging queries should use these hooks.
+               /*
+                * Apply post-paging filters on where and join. Only plugins that
+                * manipulate paging queries should use these hooks.
+                */
                if ( !$q['suppress_filters'] ) {
-                       $where          = apply_filters_ref_array( 'posts_where_paged', array( $where, &$this ) );
-                       $groupby        = apply_filters_ref_array( 'posts_groupby',             array( $groupby, &$this ) );
-                       $join           = apply_filters_ref_array( 'posts_join_paged',  array( $join, &$this ) );
-                       $orderby        = apply_filters_ref_array( 'posts_orderby',             array( $orderby, &$this ) );
-                       $distinct       = apply_filters_ref_array( 'posts_distinct',    array( $distinct, &$this ) );
-                       $limits         = apply_filters_ref_array( 'post_limits',               array( $limits, &$this ) );
-                       $fields         = apply_filters_ref_array( 'posts_fields',              array( $fields, &$this ) );
+                       /**
+                        * Filter the WHERE clause of the query.
+                        *
+                        * Specifically for manipulating paging queries.
+                        *
+                        * @since 1.5.0
+                        *
+                        * @param string   $where The WHERE clause of the query.
+                        * @param WP_Query &$this The WP_Query instance (passed by reference).
+                        */
+                       $where = apply_filters_ref_array( 'posts_where_paged', array( $where, &$this ) );
+
+                       /**
+                        * Filter the GROUP BY clause of the query.
+                        *
+                        * @since 2.0.0
+                        *
+                        * @param string   $groupby The GROUP BY clause of the query.
+                        * @param WP_Query &$this   The WP_Query instance (passed by reference).
+                        */
+                       $groupby = apply_filters_ref_array( 'posts_groupby', array( $groupby, &$this ) );
+
+                       /**
+                        * Filter the JOIN clause of the query.
+                        *
+                        * Specifically for manipulating paging queries.
+                        *
+                        * @since 1.5.0
+                        *
+                        * @param string   $join  The JOIN clause of the query.
+                        * @param WP_Query &$this The WP_Query instance (passed by reference).
+                        */
+                       $join = apply_filters_ref_array( 'posts_join_paged', array( $join, &$this ) );
+
+                       /**
+                        * Filter the ORDER BY clause of the query.
+                        *
+                        * @since 1.5.1
+                        *
+                        * @param string   $orderby The ORDER BY clause of the query.
+                        * @param WP_Query &$this   The WP_Query instance (passed by reference).
+                        */
+                       $orderby = apply_filters_ref_array( 'posts_orderby', array( $orderby, &$this ) );
+
+                       /**
+                        * Filter the DISTINCT clause of the query.
+                        *
+                        * @since 2.1.0
+                        *
+                        * @param string   $distinct The DISTINCT clause of the query.
+                        * @param WP_Query &$this    The WP_Query instance (passed by reference).
+                        */
+                       $distinct = apply_filters_ref_array( 'posts_distinct', array( $distinct, &$this ) );
+
+                       /**
+                        * Filter the LIMIT clause of the query.
+                        *
+                        * @since 2.1.0
+                        *
+                        * @param string   $limits The LIMIT clause of the query.
+                        * @param WP_Query &$this  The WP_Query instance (passed by reference).
+                        */
+                       $limits = apply_filters_ref_array( 'post_limits', array( $limits, &$this ) );
+
+                       /**
+                        * Filter the SELECT clause of the query.
+                        *
+                        * @since 2.1.0
+                        *
+                        * @param string   $fields The SELECT clause of the query.
+                        * @param WP_Query &$this  The WP_Query instance (passed by reference).
+                        */
+                       $fields = apply_filters_ref_array( 'posts_fields', array( $fields, &$this ) );
+
+                       /**
+                        * Filter all query clauses at once, for convenience.
+                        *
+                        * Covers the WHERE, GROUP BY, JOIN, ORDER BY, DISTINCT,
+                        * fields (SELECT), and LIMITS clauses.
+                        *
+                        * @since 3.1.0
+                        *
+                        * @param array    $clauses The list of clauses for the query.
+                        * @param WP_Query &$this   The WP_Query instance (passed by reference).
+                        */
+                       $clauses = (array) apply_filters_ref_array( 'posts_clauses', array( compact( $pieces ), &$this ) );
+
+                       $where = isset( $clauses[ 'where' ] ) ? $clauses[ 'where' ] : '';
+                       $groupby = isset( $clauses[ 'groupby' ] ) ? $clauses[ 'groupby' ] : '';
+                       $join = isset( $clauses[ 'join' ] ) ? $clauses[ 'join' ] : '';
+                       $orderby = isset( $clauses[ 'orderby' ] ) ? $clauses[ 'orderby' ] : '';
+                       $distinct = isset( $clauses[ 'distinct' ] ) ? $clauses[ 'distinct' ] : '';
+                       $fields = isset( $clauses[ 'fields' ] ) ? $clauses[ 'fields' ] : '';
+                       $limits = isset( $clauses[ 'limits' ] ) ? $clauses[ 'limits' ] : '';
                }
 
-               // Announce current selection parameters.  For use by caching plugins.
+               /**
+                * Fires to announce the query's current selection parameters.
+                *
+                * For use by caching plugins.
+                *
+                * @since 2.3.0
+                *
+                * @param string $selection The assembled selection query.
+                */
                do_action( 'posts_selection', $where . $groupby . $orderby . $limits . $join );
 
-               // Filter again for the benefit of caching plugins.  Regular plugins should use the hooks above.
+               /*
+                * Filter again for the benefit of caching plugins.
+                * Regular plugins should use the hooks above.
+                */
                if ( !$q['suppress_filters'] ) {
-                       $where          = apply_filters_ref_array( 'posts_where_request',       array( $where, &$this ) );
-                       $groupby        = apply_filters_ref_array( 'posts_groupby_request',             array( $groupby, &$this ) );
-                       $join           = apply_filters_ref_array( 'posts_join_request',        array( $join, &$this ) );
-                       $orderby        = apply_filters_ref_array( 'posts_orderby_request',             array( $orderby, &$this ) );
-                       $distinct       = apply_filters_ref_array( 'posts_distinct_request',    array( $distinct, &$this ) );
-                       $fields         = apply_filters_ref_array( 'posts_fields_request',              array( $fields, &$this ) );
-                       $limits         = apply_filters_ref_array( 'post_limits_request',               array( $limits, &$this ) );
+                       /**
+                        * Filter the WHERE clause of the query.
+                        *
+                        * For use by caching plugins.
+                        *
+                        * @since 2.5.0
+                        *
+                        * @param string   $where The WHERE clause of the query.
+                        * @param WP_Query &$this The WP_Query instance (passed by reference).
+                        */
+                       $where = apply_filters_ref_array( 'posts_where_request', array( $where, &$this ) );
+
+                       /**
+                        * Filter the GROUP BY clause of the query.
+                        *
+                        * For use by caching plugins.
+                        *
+                        * @since 2.5.0
+                        *
+                        * @param string   $groupby The GROUP BY clause of the query.
+                        * @param WP_Query &$this   The WP_Query instance (passed by reference).
+                        */
+                       $groupby = apply_filters_ref_array( 'posts_groupby_request', array( $groupby, &$this ) );
+
+                       /**
+                        * Filter the JOIN clause of the query.
+                        *
+                        * For use by caching plugins.
+                        *
+                        * @since 2.5.0
+                        *
+                        * @param string   $join  The JOIN clause of the query.
+                        * @param WP_Query &$this The WP_Query instance (passed by reference).
+                        */
+                       $join = apply_filters_ref_array( 'posts_join_request', array( $join, &$this ) );
+
+                       /**
+                        * Filter the ORDER BY clause of the query.
+                        *
+                        * For use by caching plugins.
+                        *
+                        * @since 2.5.0
+                        *
+                        * @param string   $orderby The ORDER BY clause of the query.
+                        * @param WP_Query &$this   The WP_Query instance (passed by reference).
+                        */
+                       $orderby = apply_filters_ref_array( 'posts_orderby_request', array( $orderby, &$this ) );
+
+                       /**
+                        * Filter the DISTINCT clause of the query.
+                        *
+                        * For use by caching plugins.
+                        *
+                        * @since 2.5.0
+                        *
+                        * @param string   $distinct The DISTINCT clause of the query.
+                        * @param WP_Query &$this    The WP_Query instance (passed by reference).
+                        */
+                       $distinct = apply_filters_ref_array( 'posts_distinct_request', array( $distinct, &$this ) );
+
+                       /**
+                        * Filter the SELECT clause of the query.
+                        *
+                        * For use by caching plugins.
+                        *
+                        * @since 2.5.0
+                        *
+                        * @param string   $fields The SELECT clause of the query.
+                        * @param WP_Query &$this  The WP_Query instance (passed by reference).
+                        */
+                       $fields = apply_filters_ref_array( 'posts_fields_request', array( $fields, &$this ) );
+
+                       /**
+                        * Filter the LIMIT clause of the query.
+                        *
+                        * For use by caching plugins.
+                        *
+                        * @since 2.5.0
+                        *
+                        * @param string   $limits The LIMIT clause of the query.
+                        * @param WP_Query &$this  The WP_Query instance (passed by reference).
+                        */
+                       $limits = apply_filters_ref_array( 'post_limits_request', array( $limits, &$this ) );
+
+                       /**
+                        * Filter all query clauses at once, for convenience.
+                        *
+                        * For use by caching plugins.
+                        *
+                        * Covers the WHERE, GROUP BY, JOIN, ORDER BY, DISTINCT,
+                        * fields (SELECT), and LIMITS clauses.
+                        *
+                        * @since 3.1.0
+                        *
+                        * @param array    $pieces The pieces of the query.
+                        * @param WP_Query &$this  The WP_Query instance (passed by reference).
+                        */
+                       $clauses = (array) apply_filters_ref_array( 'posts_clauses_request', array( compact( $pieces ), &$this ) );
+
+                       $where = isset( $clauses[ 'where' ] ) ? $clauses[ 'where' ] : '';
+                       $groupby = isset( $clauses[ 'groupby' ] ) ? $clauses[ 'groupby' ] : '';
+                       $join = isset( $clauses[ 'join' ] ) ? $clauses[ 'join' ] : '';
+                       $orderby = isset( $clauses[ 'orderby' ] ) ? $clauses[ 'orderby' ] : '';
+                       $distinct = isset( $clauses[ 'distinct' ] ) ? $clauses[ 'distinct' ] : '';
+                       $fields = isset( $clauses[ 'fields' ] ) ? $clauses[ 'fields' ] : '';
+                       $limits = isset( $clauses[ 'limits' ] ) ? $clauses[ 'limits' ] : '';
                }
 
                if ( ! empty($groupby) )
                        $groupby = 'GROUP BY ' . $groupby;
                if ( !empty( $orderby ) )
                        $orderby = 'ORDER BY ' . $orderby;
+
                $found_rows = '';
                if ( !$q['no_found_rows'] && !empty($limits) )
                        $found_rows = 'SQL_CALC_FOUND_ROWS';
 
-               $this->request = " SELECT $found_rows $distinct $fields FROM $wpdb->posts $join WHERE 1=1 $where $groupby $orderby $limits";
-               if ( !$q['suppress_filters'] )
-                       $this->request = apply_filters_ref_array('posts_request', array( $this->request, &$this ) );
+               $this->request = $old_request = "SELECT $found_rows $distinct $fields FROM $wpdb->posts $join WHERE 1=1 $where $groupby $orderby $limits";
+
+               if ( !$q['suppress_filters'] ) {
+                       /**
+                        * Filter the completed SQL query before sending.
+                        *
+                        * @since 2.0.0
+                        *
+                        * @param array    $request The complete SQL query.
+                        * @param WP_Query &$this   The WP_Query instance (passed by reference).
+                        */
+                       $this->request = apply_filters_ref_array( 'posts_request', array( $this->request, &$this ) );
+               }
+
+               if ( 'ids' == $q['fields'] ) {
+                       $this->posts = $wpdb->get_col( $this->request );
+                       $this->post_count = count( $this->posts );
+                       $this->set_found_posts( $q, $limits );
+
+                       return array_map( 'intval', $this->posts );
+               }
+
+               if ( 'id=>parent' == $q['fields'] ) {
+                       $this->posts = $wpdb->get_results( $this->request );
+                       $this->post_count = count( $this->posts );
+                       $this->set_found_posts( $q, $limits );
+
+                       $r = array();
+                       foreach ( $this->posts as $post ) {
+                               $r[ (int) $post->ID ] = (int) $post->post_parent;
+                       }
+                       return $r;
+               }
+
+               $split_the_query = ( $old_request == $this->request && "$wpdb->posts.*" == $fields && !empty( $limits ) && $q['posts_per_page'] < 500 );
+
+               /**
+                * Filter whether to split the query.
+                *
+                * Splitting the query will cause it to fetch just the IDs of the found posts
+                * (and then individually fetch each post by ID), rather than fetching every
+                * complete row at once. One massive result vs. many small results.
+                *
+                * @since 3.4.0
+                *
+                * @param bool     $split_the_query Whether or not to split the query.
+                * @param WP_Query $this            The WP_Query instance.
+                */
+               $split_the_query = apply_filters( 'split_the_query', $split_the_query, $this );
+
+               if ( $split_the_query ) {
+                       // First get the IDs and then fill in the objects
+
+                       $this->request = "SELECT $found_rows $distinct $wpdb->posts.ID FROM $wpdb->posts $join WHERE 1=1 $where $groupby $orderby $limits";
+
+                       /**
+                        * Filter the Post IDs SQL request before sending.
+                        *
+                        * @since 3.4.0
+                        *
+                        * @param string   $request The post ID request.
+                        * @param WP_Query $this    The WP_Query instance.
+                        */
+                       $this->request = apply_filters( 'posts_request_ids', $this->request, $this );
+
+                       $ids = $wpdb->get_col( $this->request );
+
+                       if ( $ids ) {
+                               $this->posts = $ids;
+                               $this->set_found_posts( $q, $limits );
+                               _prime_post_caches( $ids, $q['update_post_term_cache'], $q['update_post_meta_cache'] );
+                       } else {
+                               $this->posts = array();
+                       }
+               } else {
+                       $this->posts = $wpdb->get_results( $this->request );
+                       $this->set_found_posts( $q, $limits );
+               }
 
-               $this->posts = $wpdb->get_results($this->request);
-               // Raw results filter.  Prior to status checks.
-               if ( !$q['suppress_filters'] )
-                       $this->posts = apply_filters_ref_array('posts_results', array( $this->posts, &$this ) );
+               // Convert to WP_Post objects
+               if ( $this->posts )
+                       $this->posts = array_map( 'get_post', $this->posts );
+
+               if ( ! $q['suppress_filters'] ) {
+                       /**
+                        * Filter the raw post results array, prior to status checks.
+                        *
+                        * @since 2.3.0
+                        *
+                        * @param array    $posts The post results array.
+                        * @param WP_Query &$this The WP_Query instance (passed by reference).
+                        */
+                       $this->posts = apply_filters_ref_array( 'posts_results', array( $this->posts, &$this ) );
+               }
 
                if ( !empty($this->posts) && $this->is_comment_feed && $this->is_singular ) {
-                       $cjoin = apply_filters_ref_array('comment_feed_join', array( '', &$this ) );
-                       $cwhere = apply_filters_ref_array('comment_feed_where', array( "WHERE comment_post_ID = '{$this->posts[0]->ID}' AND comment_approved = '1'", &$this ) );
-                       $cgroupby = apply_filters_ref_array('comment_feed_groupby', array( '', &$this ) );
+                       /** This filter is documented in wp-includes/query.php */
+                       $cjoin = apply_filters_ref_array( 'comment_feed_join', array( '', &$this ) );
+
+                       /** This filter is documented in wp-includes/query.php */
+                       $cwhere = apply_filters_ref_array( 'comment_feed_where', array( "WHERE comment_post_ID = '{$this->posts[0]->ID}' AND comment_approved = '1'", &$this ) );
+
+                       /** This filter is documented in wp-includes/query.php */
+                       $cgroupby = apply_filters_ref_array( 'comment_feed_groupby', array( '', &$this ) );
                        $cgroupby = ( ! empty( $cgroupby ) ) ? 'GROUP BY ' . $cgroupby : '';
-                       $corderby = apply_filters_ref_array('comment_feed_orderby', array( 'comment_date_gmt DESC', &$this ) );
+
+                       /** This filter is documented in wp-includes/query.php */
+                       $corderby = apply_filters_ref_array( 'comment_feed_orderby', array( 'comment_date_gmt DESC', &$this ) );
                        $corderby = ( ! empty( $corderby ) ) ? 'ORDER BY ' . $corderby : '';
-                       $climits = apply_filters_ref_array('comment_feed_limits', array( 'LIMIT ' . get_option('posts_per_rss'), &$this ) );
+
+                       /** This filter is documented in wp-includes/query.php */
+                       $climits = apply_filters_ref_array( 'comment_feed_limits', array( 'LIMIT ' . get_option('posts_per_rss'), &$this ) );
+
                        $comments_request = "SELECT $wpdb->comments.* FROM $wpdb->comments $cjoin $cwhere $cgroupby $corderby $climits";
                        $this->comments = $wpdb->get_results($comments_request);
                        $this->comment_count = count($this->comments);
                }
 
-               if ( !$q['no_found_rows'] && !empty($limits) ) {
-                       $found_posts_query = apply_filters_ref_array( 'found_posts_query', array( 'SELECT FOUND_ROWS()', &$this ) );
-                       $this->found_posts = $wpdb->get_var( $found_posts_query );
-                       $this->found_posts = apply_filters_ref_array( 'found_posts', array( $this->found_posts, &$this ) );
-                       $this->max_num_pages = ceil($this->found_posts / $q['posts_per_page']);
-               }
-
                // Check post status to determine if post should be displayed.
                if ( !empty($this->posts) && ($this->is_single || $this->is_page) ) {
                        $status = get_post_status($this->posts[0]);
@@ -2466,13 +3522,22 @@ class WP_Query {
                                }
                        }
 
-                       if ( $this->is_preview && current_user_can( $edit_cap, $this->posts[0]->ID ) )
-                               $this->posts[0] = apply_filters_ref_array('the_preview', array( $this->posts[0], &$this ));
+                       if ( $this->is_preview && $this->posts && current_user_can( $edit_cap, $this->posts[0]->ID ) ) {
+                               /**
+                                * Filter the single post for preview mode.
+                                *
+                                * @since 2.7.0
+                                *
+                                * @param WP_Post  $post_preview  The Post object.
+                                * @param WP_Query &$this         The WP_Query instance (passed by reference).
+                                */
+                               $this->posts[0] = get_post( apply_filters_ref_array( 'the_preview', array( $this->posts[0], &$this ) ) );
+                       }
                }
 
                // Put sticky posts at the top of the posts array
                $sticky_posts = get_option('sticky_posts');
-               if ( $this->is_home && $page <= 1 && is_array($sticky_posts) && !empty($sticky_posts) && !$q['caller_get_posts'] ) {
+               if ( $this->is_home && $page <= 1 && is_array($sticky_posts) && !empty($sticky_posts) && !$q['ignore_sticky_posts'] ) {
                        $num_posts = count($this->posts);
                        $sticky_offset = 0;
                        // Loop over posts and relocate stickies to the front.
@@ -2483,7 +3548,7 @@ class WP_Query {
                                        array_splice($this->posts, $i, 1);
                                        // Move to front, after other stickies
                                        array_splice($this->posts, $sticky_offset, 0, array($sticky_post));
-                                       // Increment the sticky offset.  The next sticky will be placed at this offset.
+                                       // Increment the sticky offset. The next sticky will be placed at this offset.
                                        $sticky_offset++;
                                        // Remove post from sticky posts array
                                        $offset = array_search($sticky_post->ID, $sticky_posts);
@@ -2497,58 +3562,104 @@ class WP_Query {
 
                        // Fetch sticky posts that weren't in the query results
                        if ( !empty($sticky_posts) ) {
-                               $stickies__in = implode(',', array_map( 'absint', $sticky_posts ));
-                               // honor post type(s) if not set to any
-                               $stickies_where = '';
-                               if ( 'any' != $post_type && '' != $post_type ) {
-                                       if ( is_array( $post_type ) ) {
-                                               $post_types = join( "', '", $post_type );
-                                       } else {
-                                               $post_types = $post_type;
-                                       }
-                                       $stickies_where = "AND $wpdb->posts.post_type IN ('" . $post_types . "')";
-                               }
+                               $stickies = get_posts( array(
+                                       'post__in' => $sticky_posts,
+                                       'post_type' => $post_type,
+                                       'post_status' => 'publish',
+                                       'nopaging' => true
+                               ) );
 
-                               $stickies = $wpdb->get_results( "SELECT * FROM $wpdb->posts WHERE $wpdb->posts.ID IN ($stickies__in) $stickies_where" );
                                foreach ( $stickies as $sticky_post ) {
-                                       // Ignore sticky posts the current user cannot read or are not published.
-                                       if ( 'publish' != $sticky_post->post_status )
-                                               continue;
-                                       array_splice($this->posts, $sticky_offset, 0, array($sticky_post));
+                                       array_splice( $this->posts, $sticky_offset, 0, array( $sticky_post ) );
                                        $sticky_offset++;
                                }
                        }
                }
 
-               if ( !$q['suppress_filters'] )
-                       $this->posts = apply_filters_ref_array('the_posts', array( $this->posts, &$this ) );
+               if ( ! $q['suppress_filters'] ) {
+                       /**
+                        * Filter the array of retrieved posts after they've been fetched and
+                        * internally processed.
+                        *
+                        * @since 1.5.0
+                        *
+                        * @param array    $posts The array of retrieved posts.
+                        * @param WP_Query &$this The WP_Query instance (passed by reference).
+                        */
+                       $this->posts = apply_filters_ref_array( 'the_posts', array( $this->posts, &$this ) );
+               }
 
-               $this->post_count = count($this->posts);
+               // Ensure that any posts added/modified via one of the filters above are
+               // of the type WP_Post and are filtered.
+               if ( $this->posts ) {
+                       $this->post_count = count( $this->posts );
 
-               // Sanitize before caching so it'll only get done once
-               for ( $i = 0; $i < $this->post_count; $i++ ) {
-                       $this->posts[$i] = sanitize_post($this->posts[$i], 'raw');
-               }
+                       $this->posts = array_map( 'get_post', $this->posts );
 
-               if ( $q['cache_results'] )
-                       update_post_caches($this->posts, $post_type, $q['update_post_term_cache'], $q['update_post_meta_cache']);
+                       if ( $q['cache_results'] )
+                               update_post_caches($this->posts, $post_type, $q['update_post_term_cache'], $q['update_post_meta_cache']);
 
-               if ( $this->post_count > 0 ) {
-                       $this->post = $this->posts[0];
+                       $this->post = reset( $this->posts );
+               } else {
+                       $this->post_count = 0;
+                       $this->posts = array();
                }
 
                return $this->posts;
        }
 
+       /**
+        * Set up the amount of found posts and the number of pages (if limit clause was used)
+        * for the current query.
+        *
+        * @since 3.5.0
+        * @access private
+        */
+       private function set_found_posts( $q, $limits ) {
+               global $wpdb;
+
+               // Bail if posts is an empty array. Continue if posts is an empty string,
+               // null, or false to accommodate caching plugins that fill posts later.
+               if ( $q['no_found_rows'] || ( is_array( $this->posts ) && ! $this->posts ) )
+                       return;
+
+               if ( ! empty( $limits ) ) {
+                       /**
+                        * Filter the query to run for retrieving the found posts.
+                        *
+                        * @since 2.1.0
+                        *
+                        * @param string   $found_posts The query to run to find the found posts.
+                        * @param WP_Query &$this       The WP_Query instance (passed by reference).
+                        */
+                       $this->found_posts = $wpdb->get_var( apply_filters_ref_array( 'found_posts_query', array( 'SELECT FOUND_ROWS()', &$this ) ) );
+               } else {
+                       $this->found_posts = count( $this->posts );
+               }
+
+               /**
+                * Filter the number of found posts for the query.
+                *
+                * @since 2.1.0
+                *
+                * @param int      $found_posts The number of posts found.
+                * @param WP_Query &$this       The WP_Query instance (passed by reference).
+                */
+               $this->found_posts = apply_filters_ref_array( 'found_posts', array( $this->found_posts, &$this ) );
+
+               if ( ! empty( $limits ) )
+                       $this->max_num_pages = ceil( $this->found_posts / $q['posts_per_page'] );
+       }
+
        /**
         * Set up the next post and iterate current post index.
         *
         * @since 1.5.0
         * @access public
         *
-        * @return object Next post.
+        * @return WP_Post Next post.
         */
-       function next_post() {
+       public function next_post() {
 
                $this->current_post++;
 
@@ -2567,12 +3678,19 @@ class WP_Query {
         * @uses $post
         * @uses do_action_ref_array() Calls 'loop_start' if loop has just started
         */
-       function the_post() {
+       public function the_post() {
                global $post;
                $this->in_the_loop = true;
 
                if ( $this->current_post == -1 ) // loop has just started
-                       do_action_ref_array('loop_start', array(&$this));
+                       /**
+                        * Fires once the loop is started.
+                        *
+                        * @since 2.0.0
+                        *
+                        * @param WP_Query &$this The WP_Query instance (passed by reference).
+                        */
+                       do_action_ref_array( 'loop_start', array( &$this ) );
 
                $post = $this->next_post();
                setup_postdata($post);
@@ -2589,11 +3707,18 @@ class WP_Query {
         *
         * @return bool True if posts are available, false if end of loop.
         */
-       function have_posts() {
+       public function have_posts() {
                if ( $this->current_post + 1 < $this->post_count ) {
                        return true;
                } elseif ( $this->current_post + 1 == $this->post_count && $this->post_count > 0 ) {
-                       do_action_ref_array('loop_end', array(&$this));
+                       /**
+                        * Fires once the loop has ended.
+                        *
+                        * @since 2.0.0
+                        *
+                        * @param WP_Query &$this The WP_Query instance (passed by reference).
+                        */
+                       do_action_ref_array( 'loop_end', array( &$this ) );
                        // Do some cleaning up after the loop
                        $this->rewind_posts();
                }
@@ -2608,7 +3733,7 @@ class WP_Query {
         * @since 1.5.0
         * @access public
         */
-       function rewind_posts() {
+       public function rewind_posts() {
                $this->current_post = -1;
                if ( $this->post_count > 0 ) {
                        $this->post = $this->posts[0];
@@ -2623,7 +3748,7 @@ class WP_Query {
         *
         * @return object Comment object.
         */
-       function next_comment() {
+       public function next_comment() {
                $this->current_comment++;
 
                $this->comment = $this->comments[$this->current_comment];
@@ -2638,13 +3763,18 @@ class WP_Query {
         * @global object $comment Current comment.
         * @uses do_action() Calls 'comment_loop_start' hook when first comment is processed.
         */
-       function the_comment() {
+       public function the_comment() {
                global $comment;
 
                $comment = $this->next_comment();
 
                if ( $this->current_comment == 0 ) {
-                       do_action('comment_loop_start');
+                       /**
+                        * Fires once the comment loop is started.
+                        *
+                        * @since 2.2.0
+                        */
+                       do_action( 'comment_loop_start' );
                }
        }
 
@@ -2658,7 +3788,7 @@ class WP_Query {
         *
         * @return bool True, if more comments. False, if no more posts.
         */
-       function have_comments() {
+       public function have_comments() {
                if ( $this->current_comment + 1 < $this->comment_count ) {
                        return true;
                } elseif ( $this->current_comment + 1 == $this->comment_count ) {
@@ -2674,7 +3804,7 @@ class WP_Query {
         * @since 2.2.0
         * @access public
         */
-       function rewind_comments() {
+       public function rewind_comments() {
                $this->current_comment = -1;
                if ( $this->comment_count > 0 ) {
                        $this->comment = $this->comments[0];
@@ -2690,8 +3820,9 @@ class WP_Query {
         * @param string $query URL query string.
         * @return array List of posts.
         */
-       function &query($query) {
-               $this->parse_query($query);
+       public function query( $query ) {
+               $this->init();
+               $this->query = $this->query_vars = wp_parse_args( $query );
                return $this->get_posts();
        }
 
@@ -2707,50 +3838,61 @@ class WP_Query {
         *
         * @return object
         */
-       function get_queried_object() {
+       public function get_queried_object() {
                if ( isset($this->queried_object) )
                        return $this->queried_object;
 
-               $this->queried_object = NULL;
+               $this->queried_object = null;
                $this->queried_object_id = 0;
 
-               if ( $this->is_category ) {
-                       $cat = $this->get('cat');
-                       $category = &get_category($cat);
-                       if ( is_wp_error( $category ) )
-                               return NULL;
-                       $this->queried_object = &$category;
-                       $this->queried_object_id = (int) $cat;
-               } elseif ( $this->is_tag ) {
-                       $tag_id = $this->get('tag_id');
-                       $tag = &get_term($tag_id, 'post_tag');
-                       if ( is_wp_error( $tag ) )
-                               return NULL;
-                       $this->queried_object = &$tag;
-                       $this->queried_object_id = (int) $tag_id;
-               } elseif ( $this->is_tax ) {
-                       $tax = $this->get('taxonomy');
-                       $slug = $this->get('term');
-                       $term = &get_terms($tax, array( 'slug' => $slug, 'hide_empty' => false ) );
-                       if ( is_wp_error($term) || empty($term) )
-                               return NULL;
-                       $term = $term[0];
-                       $this->queried_object = $term;
-                       $this->queried_object_id = $term->term_id;
+               if ( $this->is_category || $this->is_tag || $this->is_tax ) {
+                       if ( $this->is_category ) {
+                               if ( $this->get( 'cat' ) ) {
+                                       $term = get_term( $this->get( 'cat' ), 'category' );
+                               } elseif ( $this->get( 'category_name' ) ) {
+                                       $term = get_term_by( 'slug', $this->get( 'category_name' ), 'category' );
+                               }
+                       } elseif ( $this->is_tag ) {
+                               if ( $this->get( 'tag_id' ) ) {
+                                       $term = get_term( $this->get( 'tag_id' ), 'post_tag' );
+                               } elseif ( $this->get( 'tag' ) ) {
+                                       $term = get_term_by( 'slug', $this->get( 'tag' ), 'post_tag' );
+                               }
+                       } else {
+                               $tax_query_in_and = wp_list_filter( $this->tax_query->queries, array( 'operator' => 'NOT IN' ), 'NOT' );
+                               $query = reset( $tax_query_in_and );
+
+                               if ( $query['terms'] ) {
+                                       if ( 'term_id' == $query['field'] ) {
+                                               $term = get_term( reset( $query['terms'] ), $query['taxonomy'] );
+                                       } else {
+                                               $term = get_term_by( $query['field'], reset( $query['terms'] ), $query['taxonomy'] );
+                                       }
+                               }
+                       }
+
+                       if ( ! empty( $term ) && ! is_wp_error( $term ) )  {
+                               $this->queried_object = $term;
+                               $this->queried_object_id = (int) $term->term_id;
+
+                               if ( $this->is_category && 'category' === $this->queried_object->taxonomy )
+                                       _make_cat_compat( $this->queried_object );
+                       }
+               } elseif ( $this->is_post_type_archive ) {
+                       $post_type = $this->get( 'post_type' );
+                       if ( is_array( $post_type ) )
+                               $post_type = reset( $post_type );
+                       $this->queried_object = get_post_type_object( $post_type );
                } elseif ( $this->is_posts_page ) {
-                       $this->queried_object = & get_page(get_option('page_for_posts'));
+                       $page_for_posts = get_option('page_for_posts');
+                       $this->queried_object = get_post( $page_for_posts );
                        $this->queried_object_id = (int) $this->queried_object->ID;
-               } elseif ( $this->is_single && !is_null($this->post) ) {
-                       $this->queried_object = $this->post;
-                       $this->queried_object_id = (int) $this->post->ID;
-               } elseif ( $this->is_page && !is_null($this->post) ) {
+               } elseif ( $this->is_singular && ! empty( $this->post ) ) {
                        $this->queried_object = $this->post;
                        $this->queried_object_id = (int) $this->post->ID;
                } elseif ( $this->is_author ) {
-                       $author_id = (int) $this->get('author');
-                       $author = get_userdata($author_id);
-                       $this->queried_object = $author;
-                       $this->queried_object_id = $author_id;
+                       $this->queried_object_id = (int) $this->get('author');
+                       $this->queried_object = get_userdata( $this->queried_object_id );
                }
 
                return $this->queried_object;
@@ -2764,7 +3906,7 @@ class WP_Query {
         *
         * @return int
         */
-       function get_queried_object_id() {
+       public function get_queried_object_id() {
                $this->get_queried_object();
 
                if ( isset($this->queried_object_id) ) {
@@ -2775,7 +3917,7 @@ class WP_Query {
        }
 
        /**
-        * PHP4 type constructor.
+        * Constructor.
         *
         * Sets up the WordPress query, if parameter is not empty.
         *
@@ -2785,11 +3927,620 @@ class WP_Query {
         * @param string $query URL query string.
         * @return WP_Query
         */
-       function WP_Query($query = '') {
+       public function __construct($query = '') {
                if ( ! empty($query) ) {
                        $this->query($query);
                }
        }
+
+       /**
+        * Make private properties readable for backwards compatibility.
+        *
+        * @since 4.0.0
+        * @access public
+        *
+        * @param string $name Property to get.
+        * @return mixed Property.
+        */
+       public function __get( $name ) {
+               return $this->$name;
+       }
+
+       /**
+        * Make private properties settable for backwards compatibility.
+        *
+        * @since 4.0.0
+        * @access public
+        *
+        * @param string $name Property to check if set.
+        * @return bool Whether the property is set.
+        */
+       public function __isset( $name ) {
+               return isset( $this->$name );
+       }
+
+       /**
+        * Make private properties settable for backwards compatibility.
+        *
+        * @since 4.0.0
+        * @access public
+        *
+        * @param string $name Property to unset.
+        */
+       public function __unset( $name ) {
+               unset( $this->$name );
+       }
+
+       /**
+        * Make private/protected methods readable for backwards compatibility.
+        *
+        * @since 4.0.0
+        * @access public
+        *
+        * @param callable $name      Method to call.
+        * @param array    $arguments Arguments to pass when calling.
+        * @return mixed|bool Return value of the callback, otherwise false.
+        */
+       public function __call( $name, $arguments ) {
+               return call_user_func_array( array( $this, $name ), $arguments );
+       }
+
+       /**
+        * Is the query for an existing archive page?
+        *
+        * Month, Year, Category, Author, Post Type archive...
+        *
+        * @since 3.1.0
+        *
+        * @return bool
+        */
+       public function is_archive() {
+               return (bool) $this->is_archive;
+       }
+
+       /**
+        * Is the query for an existing post type archive page?
+        *
+        * @since 3.1.0
+        *
+        * @param mixed $post_types Optional. Post type or array of posts types to check against.
+        * @return bool
+        */
+       public function is_post_type_archive( $post_types = '' ) {
+               if ( empty( $post_types ) || ! $this->is_post_type_archive )
+                       return (bool) $this->is_post_type_archive;
+
+               $post_type = $this->get( 'post_type' );
+               if ( is_array( $post_type ) )
+                       $post_type = reset( $post_type );
+               $post_type_object = get_post_type_object( $post_type );
+
+               return in_array( $post_type_object->name, (array) $post_types );
+       }
+
+       /**
+        * Is the query for an existing attachment page?
+        *
+        * @since 3.1.0
+        *
+        * @param mixed $attachment Attachment ID, title, slug, or array of such.
+        * @return bool
+        */
+       public function is_attachment( $attachment = '' ) {
+               if ( ! $this->is_attachment ) {
+                       return false;
+               }
+
+               if ( empty( $attachment ) ) {
+                       return true;
+               }
+
+               $attachment = (array) $attachment;
+
+               $post_obj = $this->get_queried_object();
+
+               if ( in_array( $post_obj->ID, $attachment ) ) {
+                       return true;
+               } elseif ( in_array( $post_obj->post_title, $attachment ) ) {
+                       return true;
+               } elseif ( in_array( $post_obj->post_name, $attachment ) ) {
+                       return true;
+               }
+               return false;
+       }
+
+       /**
+        * Is the query for an existing author archive page?
+        *
+        * If the $author parameter is specified, this function will additionally
+        * check if the query is for one of the authors specified.
+        *
+        * @since 3.1.0
+        *
+        * @param mixed $author Optional. User ID, nickname, nicename, or array of User IDs, nicknames, and nicenames
+        * @return bool
+        */
+       public function is_author( $author = '' ) {
+               if ( !$this->is_author )
+                       return false;
+
+               if ( empty($author) )
+                       return true;
+
+               $author_obj = $this->get_queried_object();
+
+               $author = (array) $author;
+
+               if ( in_array( $author_obj->ID, $author ) )
+                       return true;
+               elseif ( in_array( $author_obj->nickname, $author ) )
+                       return true;
+               elseif ( in_array( $author_obj->user_nicename, $author ) )
+                       return true;
+
+               return false;
+       }
+
+       /**
+        * Is the query for an existing category archive page?
+        *
+        * If the $category parameter is specified, this function will additionally
+        * check if the query is for one of the categories specified.
+        *
+        * @since 3.1.0
+        *
+        * @param mixed $category Optional. Category ID, name, slug, or array of Category IDs, names, and slugs.
+        * @return bool
+        */
+       public function is_category( $category = '' ) {
+               if ( !$this->is_category )
+                       return false;
+
+               if ( empty($category) )
+                       return true;
+
+               $cat_obj = $this->get_queried_object();
+
+               $category = (array) $category;
+
+               if ( in_array( $cat_obj->term_id, $category ) )
+                       return true;
+               elseif ( in_array( $cat_obj->name, $category ) )
+                       return true;
+               elseif ( in_array( $cat_obj->slug, $category ) )
+                       return true;
+
+               return false;
+       }
+
+       /**
+        * Is the query for an existing tag archive page?
+        *
+        * If the $tag parameter is specified, this function will additionally
+        * check if the query is for one of the tags specified.
+        *
+        * @since 3.1.0
+        *
+        * @param mixed $tag Optional. Tag ID, name, slug, or array of Tag IDs, names, and slugs.
+        * @return bool
+        */
+       public function is_tag( $tag = '' ) {
+               if ( ! $this->is_tag )
+                       return false;
+
+               if ( empty( $tag ) )
+                       return true;
+
+               $tag_obj = $this->get_queried_object();
+
+               $tag = (array) $tag;
+
+               if ( in_array( $tag_obj->term_id, $tag ) )
+                       return true;
+               elseif ( in_array( $tag_obj->name, $tag ) )
+                       return true;
+               elseif ( in_array( $tag_obj->slug, $tag ) )
+                       return true;
+
+               return false;
+       }
+
+       /**
+        * Is the query for an existing taxonomy archive page?
+        *
+        * If the $taxonomy parameter is specified, this function will additionally
+        * check if the query is for that specific $taxonomy.
+        *
+        * If the $term parameter is specified in addition to the $taxonomy parameter,
+        * this function will additionally check if the query is for one of the terms
+        * specified.
+        *
+        * @since 3.1.0
+        *
+        * @param mixed $taxonomy Optional. Taxonomy slug or slugs.
+        * @param mixed $term. Optional. Term ID, name, slug or array of Term IDs, names, and slugs.
+        * @return bool
+        */
+       public function is_tax( $taxonomy = '', $term = '' ) {
+               global $wp_taxonomies;
+
+               if ( !$this->is_tax )
+                       return false;
+
+               if ( empty( $taxonomy ) )
+                       return true;
+
+               $queried_object = $this->get_queried_object();
+               $tax_array = array_intersect( array_keys( $wp_taxonomies ), (array) $taxonomy );
+               $term_array = (array) $term;
+
+               // Check that the taxonomy matches.
+               if ( ! ( isset( $queried_object->taxonomy ) && count( $tax_array ) && in_array( $queried_object->taxonomy, $tax_array ) ) )
+                       return false;
+
+               // Only a Taxonomy provided.
+               if ( empty( $term ) )
+                       return true;
+
+               return isset( $queried_object->term_id ) &&
+                       count( array_intersect(
+                               array( $queried_object->term_id, $queried_object->name, $queried_object->slug ),
+                               $term_array
+                       ) );
+       }
+
+       /**
+        * Whether the current URL is within the comments popup window.
+        *
+        * @since 3.1.0
+        *
+        * @return bool
+        */
+       public function is_comments_popup() {
+               return (bool) $this->is_comments_popup;
+       }
+
+       /**
+        * Is the query for an existing date archive?
+        *
+        * @since 3.1.0
+        *
+        * @return bool
+        */
+       public function is_date() {
+               return (bool) $this->is_date;
+       }
+
+       /**
+        * Is the query for an existing day archive?
+        *
+        * @since 3.1.0
+        *
+        * @return bool
+        */
+       public function is_day() {
+               return (bool) $this->is_day;
+       }
+
+       /**
+        * Is the query for a feed?
+        *
+        * @since 3.1.0
+        *
+        * @param string|array $feeds Optional feed types to check.
+        * @return bool
+        */
+       public function is_feed( $feeds = '' ) {
+               if ( empty( $feeds ) || ! $this->is_feed )
+                       return (bool) $this->is_feed;
+               $qv = $this->get( 'feed' );
+               if ( 'feed' == $qv )
+                       $qv = get_default_feed();
+               return in_array( $qv, (array) $feeds );
+       }
+
+       /**
+        * Is the query for a comments feed?
+        *
+        * @since 3.1.0
+        *
+        * @return bool
+        */
+       public function is_comment_feed() {
+               return (bool) $this->is_comment_feed;
+       }
+
+       /**
+        * Is the query for the front page of the site?
+        *
+        * This is for what is displayed at your site's main URL.
+        *
+        * Depends on the site's "Front page displays" Reading Settings 'show_on_front' and 'page_on_front'.
+        *
+        * If you set a static page for the front page of your site, this function will return
+        * true when viewing that page.
+        *
+        * Otherwise the same as @see WP_Query::is_home()
+        *
+        * @since 3.1.0
+        * @uses is_home()
+        * @uses get_option()
+        *
+        * @return bool True, if front of site.
+        */
+       public function is_front_page() {
+               // most likely case
+               if ( 'posts' == get_option( 'show_on_front') && $this->is_home() )
+                       return true;
+               elseif ( 'page' == get_option( 'show_on_front') && get_option( 'page_on_front' ) && $this->is_page( get_option( 'page_on_front' ) ) )
+                       return true;
+               else
+                       return false;
+       }
+
+       /**
+        * Is the query for the blog homepage?
+        *
+        * This is the page which shows the time based blog content of your site.
+        *
+        * Depends on the site's "Front page displays" Reading Settings 'show_on_front' and 'page_for_posts'.
+        *
+        * If you set a static page for the front page of your site, this function will return
+        * true only on the page you set as the "Posts page".
+        *
+        * @see WP_Query::is_front_page()
+        *
+        * @since 3.1.0
+        *
+        * @return bool True if blog view homepage.
+        */
+       public function is_home() {
+               return (bool) $this->is_home;
+       }
+
+       /**
+        * Is the query for an existing month archive?
+        *
+        * @since 3.1.0
+        *
+        * @return bool
+        */
+       public function is_month() {
+               return (bool) $this->is_month;
+       }
+
+       /**
+        * Is the query for an existing single page?
+        *
+        * If the $page parameter is specified, this function will additionally
+        * check if the query is for one of the pages specified.
+        *
+        * @see WP_Query::is_single()
+        * @see WP_Query::is_singular()
+        *
+        * @since 3.1.0
+        *
+        * @param mixed $page Page ID, title, slug, path, or array of such.
+        * @return bool
+        */
+       public function is_page( $page = '' ) {
+               if ( !$this->is_page )
+                       return false;
+
+               if ( empty( $page ) )
+                       return true;
+
+               $page_obj = $this->get_queried_object();
+
+               $page = (array) $page;
+
+               if ( in_array( $page_obj->ID, $page ) ) {
+                       return true;
+               } elseif ( in_array( $page_obj->post_title, $page ) ) {
+                       return true;
+               } else if ( in_array( $page_obj->post_name, $page ) ) {
+                       return true;
+               } else {
+                       foreach ( $page as $pagepath ) {
+                               if ( ! strpos( $pagepath, '/' ) ) {
+                                       continue;
+                               }
+                               $pagepath_obj = get_page_by_path( $pagepath );
+
+                               if ( $pagepath_obj && ( $pagepath_obj->ID == $page_obj->ID ) ) {
+                                       return true;
+                               }
+                       }
+               }
+
+               return false;
+       }
+
+       /**
+        * Is the query for paged result and not for the first page?
+        *
+        * @since 3.1.0
+        *
+        * @return bool
+        */
+       public function is_paged() {
+               return (bool) $this->is_paged;
+       }
+
+       /**
+        * Is the query for a post or page preview?
+        *
+        * @since 3.1.0
+        *
+        * @return bool
+        */
+       public function is_preview() {
+               return (bool) $this->is_preview;
+       }
+
+       /**
+        * Is the query for the robots file?
+        *
+        * @since 3.1.0
+        *
+        * @return bool
+        */
+       public function is_robots() {
+               return (bool) $this->is_robots;
+       }
+
+       /**
+        * Is the query for a search?
+        *
+        * @since 3.1.0
+        *
+        * @return bool
+        */
+       public function is_search() {
+               return (bool) $this->is_search;
+       }
+
+       /**
+        * Is the query for an existing single post?
+        *
+        * Works for any post type, except attachments and pages
+        *
+        * If the $post parameter is specified, this function will additionally
+        * check if the query is for one of the Posts specified.
+        *
+        * @see WP_Query::is_page()
+        * @see WP_Query::is_singular()
+        *
+        * @since 3.1.0
+        *
+        * @param mixed $post Post ID, title, slug, path, or array of such.
+        * @return bool
+        */
+       public function is_single( $post = '' ) {
+               if ( !$this->is_single )
+                       return false;
+
+               if ( empty($post) )
+                       return true;
+
+               $post_obj = $this->get_queried_object();
+
+               $post = (array) $post;
+
+               if ( in_array( $post_obj->ID, $post ) ) {
+                       return true;
+               } elseif ( in_array( $post_obj->post_title, $post ) ) {
+                       return true;
+               } elseif ( in_array( $post_obj->post_name, $post ) ) {
+                       return true;
+               } else {
+                       foreach ( $post as $postpath ) {
+                               if ( ! strpos( $postpath, '/' ) ) {
+                                       continue;
+                               }
+                               $postpath_obj = get_page_by_path( $postpath, OBJECT, $post_obj->post_type );
+
+                               if ( $postpath_obj && ( $postpath_obj->ID == $post_obj->ID ) ) {
+                                       return true;
+                               }
+                       }
+               }
+               return false;
+       }
+
+       /**
+        * Is the query for an existing single post of any post type (post, attachment, page, ... )?
+        *
+        * If the $post_types parameter is specified, this function will additionally
+        * check if the query is for one of the Posts Types specified.
+        *
+        * @see WP_Query::is_page()
+        * @see WP_Query::is_single()
+        *
+        * @since 3.1.0
+        *
+        * @param mixed $post_types Optional. Post Type or array of Post Types
+        * @return bool
+        */
+       public function is_singular( $post_types = '' ) {
+               if ( empty( $post_types ) || !$this->is_singular )
+                       return (bool) $this->is_singular;
+
+               $post_obj = $this->get_queried_object();
+
+               return in_array( $post_obj->post_type, (array) $post_types );
+       }
+
+       /**
+        * Is the query for a specific time?
+        *
+        * @since 3.1.0
+        *
+        * @return bool
+        */
+       public function is_time() {
+               return (bool) $this->is_time;
+       }
+
+       /**
+        * Is the query for a trackback endpoint call?
+        *
+        * @since 3.1.0
+        *
+        * @return bool
+        */
+       public function is_trackback() {
+               return (bool) $this->is_trackback;
+       }
+
+       /**
+        * Is the query for an existing year archive?
+        *
+        * @since 3.1.0
+        *
+        * @return bool
+        */
+       public function is_year() {
+               return (bool) $this->is_year;
+       }
+
+       /**
+        * Is the query a 404 (returns no results)?
+        *
+        * @since 3.1.0
+        *
+        * @return bool
+        */
+       public function is_404() {
+               return (bool) $this->is_404;
+       }
+
+       /**
+        * Is the query the main query?
+        *
+        * @since 3.3.0
+        *
+        * @return bool
+        */
+       public function is_main_query() {
+               global $wp_the_query;
+               return $wp_the_query === $this;
+       }
+
+       /**
+        * After looping through a nested query, this function
+        * restores the $post global to the current post in this query.
+        *
+        * @since 3.7.0
+        *
+        * @return bool
+        */
+       public function reset_postdata() {
+               if ( ! empty( $this->post ) ) {
+                       $GLOBALS['post'] = $this->post;
+                       setup_postdata( $this->post );
+               }
+       }
 }
 
 /**
@@ -2808,20 +4559,38 @@ function wp_old_slug_redirect() {
        if ( is_404() && '' != $wp_query->query_vars['name'] ) :
                global $wpdb;
 
-               $query = "SELECT post_id FROM $wpdb->postmeta, $wpdb->posts WHERE ID = post_id AND meta_key = '_wp_old_slug' AND meta_value='" . $wp_query->query_vars['name'] . "'";
+               // Guess the current post_type based on the query vars.
+               if ( get_query_var('post_type') )
+                       $post_type = get_query_var('post_type');
+               elseif ( !empty($wp_query->query_vars['pagename']) )
+                       $post_type = 'page';
+               else
+                       $post_type = 'post';
+
+               if ( is_array( $post_type ) ) {
+                       if ( count( $post_type ) > 1 )
+                               return;
+                       $post_type = array_shift( $post_type );
+               }
+
+               // Do not attempt redirect for hierarchical post types
+               if ( is_post_type_hierarchical( $post_type ) )
+                       return;
+
+               $query = $wpdb->prepare("SELECT post_id FROM $wpdb->postmeta, $wpdb->posts WHERE ID = post_id AND post_type = %s AND meta_key = '_wp_old_slug' AND meta_value = %s", $post_type, $wp_query->query_vars['name']);
 
                // if year, monthnum, or day have been specified, make our query more precise
                // just in case there are multiple identical _wp_old_slug values
                if ( '' != $wp_query->query_vars['year'] )
-                       $query .= " AND YEAR(post_date) = '{$wp_query->query_vars['year']}'";
+                       $query .= $wpdb->prepare(" AND YEAR(post_date) = %d", $wp_query->query_vars['year']);
                if ( '' != $wp_query->query_vars['monthnum'] )
-                       $query .= " AND MONTH(post_date) = '{$wp_query->query_vars['monthnum']}'";
+                       $query .= $wpdb->prepare(" AND MONTH(post_date) = %d", $wp_query->query_vars['monthnum']);
                if ( '' != $wp_query->query_vars['day'] )
-                       $query .= " AND DAYOFMONTH(post_date) = '{$wp_query->query_vars['day']}'";
+                       $query .= $wpdb->prepare(" AND DAYOFMONTH(post_date) = %d", $wp_query->query_vars['day']);
 
                $id = (int) $wpdb->get_var($query);
 
-               if ( !$id )
+               if ( ! $id )
                        return;
 
                $link = get_permalink($id);
@@ -2829,7 +4598,7 @@ function wp_old_slug_redirect() {
                if ( !$link )
                        return;
 
-               wp_redirect($link, '301'); // Permanent redirect
+               wp_redirect( $link, 301 ); // Permanent redirect
                exit;
        endif;
 }
@@ -2843,38 +4612,48 @@ function wp_old_slug_redirect() {
  * @uses do_action_ref_array() Calls 'the_post'
  * @return bool True when finished.
  */
-function setup_postdata($post) {
-       global $id, $authordata, $day, $currentmonth, $page, $pages, $multipage, $more, $numpages;
+function setup_postdata( $post ) {
+       global $id, $authordata, $currentday, $currentmonth, $page, $pages, $multipage, $more, $numpages;
 
        $id = (int) $post->ID;
 
        $authordata = get_userdata($post->post_author);
 
-       $day = mysql2date('d.m.y', $post->post_date, false);
+       $currentday = mysql2date('d.m.y', $post->post_date, false);
        $currentmonth = mysql2date('m', $post->post_date, false);
        $numpages = 1;
+       $multipage = 0;
        $page = get_query_var('page');
-       if ( !$page )
+       if ( ! $page )
                $page = 1;
        if ( is_single() || is_page() || is_feed() )
                $more = 1;
        $content = $post->post_content;
-       if ( strpos( $content, '<!--nextpage-->' ) ) {
+       if ( false !== strpos( $content, '<!--nextpage-->' ) ) {
                if ( $page > 1 )
                        $more = 1;
-               $multipage = 1;
-               $content = str_replace("\n<!--nextpage-->\n", '<!--nextpage-->', $content);
-               $content = str_replace("\n<!--nextpage-->", '<!--nextpage-->', $content);
-               $content = str_replace("<!--nextpage-->\n", '<!--nextpage-->', $content);
+               $content = str_replace( "\n<!--nextpage-->\n", '<!--nextpage-->', $content );
+               $content = str_replace( "\n<!--nextpage-->", '<!--nextpage-->', $content );
+               $content = str_replace( "<!--nextpage-->\n", '<!--nextpage-->', $content );
+               // Ignore nextpage at the beginning of the content.
+               if ( 0 === strpos( $content, '<!--nextpage-->' ) )
+                       $content = substr( $content, 15 );
                $pages = explode('<!--nextpage-->', $content);
                $numpages = count($pages);
+               if ( $numpages > 1 )
+                       $multipage = 1;
        } else {
                $pages = array( $post->post_content );
-               $multipage = 0;
        }
 
-       do_action_ref_array('the_post', array(&$post));
+       /**
+        * Fires once the post data has been setup.
+        *
+        * @since 2.8.0
+        *
+        * @param WP_Post &$post The Post object (passed by reference).
+        */
+       do_action_ref_array( 'the_post', array( &$post ) );
 
        return true;
 }
-?>