wp-includes/canonical.php

   1 <?php
   2 /**
   3  * Canonical API to handle WordPress Redirecting
   4  *
   5  * Based on "Permalink Redirect" from Scott Yang and "Enforce www. Preference"
   6  * by Mark Jaquith
   7  *
   8  * @package WordPress
   9  * @since 2.3.0
  10  */
  11
  12 /**
  13  * Redirects incoming links to the proper URL based on the site url.
  14  *
  15  * Search engines consider www.somedomain.com and somedomain.com to be two
  16  * different URLs when they both go to the same location. This SEO enhancement
  17  * prevents penalty for duplicate content by redirecting all incoming links to
  18  * one or the other.
  19  *
  20  * Prevents redirection for feeds, trackbacks, searches, and
  21  * admin URLs. Does not redirect on non-pretty-permalink-supporting IIS 7+,
  22  * page/post previews, WP admin, Trackbacks, robots.txt, searches, or on POST
  23  * requests.
  24  *
  25  * Will also attempt to find the correct link when a user enters a URL that does
  26  * not exist based on exact WordPress query. Will instead try to parse the URL
  27  * or query in an attempt to figure the correct page to go to.
  28  *
  29  * @since 2.3.0
  30  *
  31  * @global WP_Rewrite $wp_rewrite
  32  * @global bool $is_IIS
  33  * @global WP_Query $wp_query
  34  * @global wpdb $wpdb WordPress database abstraction object.
  35  *
  36  * @param string $requested_url Optional. The URL that was requested, used to
  37  *              figure if redirect is needed.
  38  * @param bool $do_redirect Optional. Redirect to the new URL.
  39  * @return string|void The string of the URL, if redirect needed.
  40  */
  41 function redirect_canonical( $requested_url = null, $do_redirect = true ) {
  42         global $wp_rewrite, $is_IIS, $wp_query, $wpdb, $wp;
  43
  44         if ( isset( $_SERVER['REQUEST_METHOD'] ) && ! in_array( strtoupper( $_SERVER['REQUEST_METHOD'] ), array( 'GET', 'HEAD' ) ) ) {
  45                 return;
  46         }
  47
  48         // If we're not in wp-admin and the post has been published and preview nonce
  49         // is non-existent or invalid then no need for preview in query
  50         if ( is_preview() && get_query_var( 'p' ) && 'publish' == get_post_status( get_query_var( 'p' ) ) ) {
  51                 if ( ! isset( $_GET['preview_id'] )
  52                         || ! isset( $_GET['preview_nonce'] )
  53                         || ! wp_verify_nonce( $_GET['preview_nonce'], 'post_preview_' . (int) $_GET['preview_id'] ) ) {
  54                         $wp_query->is_preview = false;
  55                 }
  56         }
  57
  58         if ( is_trackback() || is_search() || is_admin() || is_preview() || is_robots() || ( $is_IIS && !iis7_supports_permalinks() ) ) {
  59                 return;
  60         }
  61
  62         if ( ! $requested_url && isset( $_SERVER['HTTP_HOST'] ) ) {
  63                 // build the URL in the address bar
  64                 $requested_url  = is_ssl() ? 'https://' : 'http://';
  65                 $requested_url .= $_SERVER['HTTP_HOST'];
  66                 $requested_url .= $_SERVER['REQUEST_URI'];
  67         }
  68
  69         $original = @parse_url($requested_url);
  70         if ( false === $original ) {
  71                 return;
  72         }
  73
  74         $redirect = $original;
  75         $redirect_url = false;
  76
  77         // Notice fixing
  78         if ( !isset($redirect['path']) )
  79                 $redirect['path'] = '';
  80         if ( !isset($redirect['query']) )
  81                 $redirect['query'] = '';
  82
  83         // If the original URL ended with non-breaking spaces, they were almost
  84         // certainly inserted by accident. Let's remove them, so the reader doesn't
  85         // see a 404 error with no obvious cause.
  86         $redirect['path'] = preg_replace( '|(%C2%A0)+$|i', '', $redirect['path'] );
  87
  88         // It's not a preview, so remove it from URL
  89         if ( get_query_var( 'preview' ) ) {
  90                 $redirect['query'] = remove_query_arg( 'preview', $redirect['query'] );
  91         }
  92
  93         if ( is_feed() && ( $id = get_query_var( 'p' ) ) ) {
  94                 if ( $redirect_url = get_post_comments_feed_link( $id, get_query_var( 'feed' ) ) ) {
  95                         $redirect['query'] = _remove_qs_args_if_not_in_url( $redirect['query'], array( 'p', 'page_id', 'attachment_id', 'pagename', 'name', 'post_type', 'feed'), $redirect_url );
  96                         $redirect['path'] = parse_url( $redirect_url, PHP_URL_PATH );
  97                 }
  98         }
  99
 100         if ( is_singular() && 1 > $wp_query->post_count && ($id = get_query_var('p')) ) {
 101
 102                 $vars = $wpdb->get_results( $wpdb->prepare("SELECT post_type, post_parent FROM $wpdb->posts WHERE ID = %d", $id) );
 103
 104                 if ( isset($vars[0]) && $vars = $vars[0] ) {
 105                         if ( 'revision' == $vars->post_type && $vars->post_parent > 0 )
 106                                 $id = $vars->post_parent;
 107
 108                         if ( $redirect_url = get_permalink($id) )
 109                                 $redirect['query'] = _remove_qs_args_if_not_in_url( $redirect['query'], array( 'p', 'page_id', 'attachment_id', 'pagename', 'name', 'post_type' ), $redirect_url );
 110                 }
 111         }
 112
 113         // These tests give us a WP-generated permalink
 114         if ( is_404() ) {
 115
 116                 // Redirect ?page_id, ?p=, ?attachment_id= to their respective url's
 117                 $id = max( get_query_var('p'), get_query_var('page_id'), get_query_var('attachment_id') );
 118                 if ( $id && $redirect_post = get_post($id) ) {
 119                         $post_type_obj = get_post_type_object($redirect_post->post_type);
 120                         if ( $post_type_obj->public && 'auto-draft' != $redirect_post->post_status ) {
 121                                 $redirect_url = get_permalink($redirect_post);
 122                                 $redirect['query'] = _remove_qs_args_if_not_in_url( $redirect['query'], array( 'p', 'page_id', 'attachment_id', 'pagename', 'name', 'post_type' ), $redirect_url );
 123                         }
 124                 }
 125
 126                 if ( get_query_var( 'day' ) && get_query_var( 'monthnum' ) && get_query_var( 'year' ) ) {
 127                         $year  = get_query_var( 'year' );
 128                         $month = get_query_var( 'monthnum' );
 129                         $day   = get_query_var( 'day' );
 130                         $date  = sprintf( '%04d-%02d-%02d', $year, $month, $day );
 131                         if ( ! wp_checkdate( $month, $day, $year, $date ) ) {
 132                                 $redirect_url = get_month_link( $year, $month );
 133                                 $redirect['query'] = _remove_qs_args_if_not_in_url( $redirect['query'], array( 'year', 'monthnum', 'day' ), $redirect_url );
 134                         }
 135                 } elseif ( get_query_var( 'monthnum' ) && get_query_var( 'year' ) && 12 < get_query_var( 'monthnum' ) ) {
 136                         $redirect_url = get_year_link( get_query_var( 'year' ) );
 137                         $redirect['query'] = _remove_qs_args_if_not_in_url( $redirect['query'], array( 'year', 'monthnum' ), $redirect_url );
 138                 }
 139
 140                 if ( ! $redirect_url ) {
 141                         if ( $redirect_url = redirect_guess_404_permalink() ) {
 142                                 $redirect['query'] = _remove_qs_args_if_not_in_url( $redirect['query'], array( 'page', 'feed', 'p', 'page_id', 'attachment_id', 'pagename', 'name', 'post_type' ), $redirect_url );
 143                         }
 144                 }
 145
 146                 if ( get_query_var( 'page' ) && $wp_query->post &&
 147                         false !== strpos( $wp_query->post->post_content, '<!--nextpage-->' ) ) {
 148                         $redirect['path'] = rtrim( $redirect['path'], (int) get_query_var( 'page' ) . '/' );
 149                         $redirect['query'] = remove_query_arg( 'page', $redirect['query'] );
 150                         $redirect_url = get_permalink( $wp_query->post->ID );
 151                 }
 152
 153         } elseif ( is_object($wp_rewrite) && $wp_rewrite->using_permalinks() ) {
 154                 // rewriting of old ?p=X, ?m=2004, ?m=200401, ?m=20040101
 155                 if ( is_attachment() &&
 156                         ! array_diff( array_keys( $wp->query_vars ), array( 'attachment', 'attachment_id' ) ) &&
 157                         ! $redirect_url ) {
 158                         if ( ! empty( $_GET['attachment_id'] ) ) {
 159                                 $redirect_url = get_attachment_link( get_query_var( 'attachment_id' ) );
 160                                 if ( $redirect_url ) {
 161                                         $redirect['query'] = remove_query_arg( 'attachment_id', $redirect['query'] );
 162                                 }
 163                         } else {
 164                                 $redirect_url = get_attachment_link();
 165                         }
 166                 } elseif ( is_single() && !empty($_GET['p']) && ! $redirect_url ) {
 167                         if ( $redirect_url = get_permalink(get_query_var('p')) )
 168                                 $redirect['query'] = remove_query_arg(array('p', 'post_type'), $redirect['query']);
 169                 } elseif ( is_single() && !empty($_GET['name'])  && ! $redirect_url ) {
 170                         if ( $redirect_url = get_permalink( $wp_query->get_queried_object_id() ) )
 171                                 $redirect['query'] = remove_query_arg('name', $redirect['query']);
 172                 } elseif ( is_page() && !empty($_GET['page_id']) && ! $redirect_url ) {
 173                         if ( $redirect_url = get_permalink(get_query_var('page_id')) )
 174                                 $redirect['query'] = remove_query_arg('page_id', $redirect['query']);
 175                 } elseif ( is_page() && !is_feed() && 'page' == get_option('show_on_front') && get_queried_object_id() == get_option('page_on_front')  && ! $redirect_url ) {
 176                         $redirect_url = home_url('/');
 177                 } elseif ( is_home() && !empty($_GET['page_id']) && 'page' == get_option('show_on_front') && get_query_var('page_id') == get_option('page_for_posts')  && ! $redirect_url ) {
 178                         if ( $redirect_url = get_permalink(get_option('page_for_posts')) )
 179                                 $redirect['query'] = remove_query_arg('page_id', $redirect['query']);
 180                 } elseif ( !empty($_GET['m']) && ( is_year() || is_month() || is_day() ) ) {
 181                         $m = get_query_var('m');
 182                         switch ( strlen($m) ) {
 183                                 case 4: // Yearly
 184                                         $redirect_url = get_year_link($m);
 185                                         break;
 186                                 case 6: // Monthly
 187                                         $redirect_url = get_month_link( substr($m, 0, 4), substr($m, 4, 2) );
 188                                         break;
 189                                 case 8: // Daily
 190                                         $redirect_url = get_day_link(substr($m, 0, 4), substr($m, 4, 2), substr($m, 6, 2));
 191                                         break;
 192                         }
 193                         if ( $redirect_url )
 194                                 $redirect['query'] = remove_query_arg('m', $redirect['query']);
 195                 // now moving on to non ?m=X year/month/day links
 196                 } elseif ( is_day() && get_query_var('year') && get_query_var('monthnum') && !empty($_GET['day']) ) {
 197                         if ( $redirect_url = get_day_link(get_query_var('year'), get_query_var('monthnum'), get_query_var('day')) )
 198                                 $redirect['query'] = remove_query_arg(array('year', 'monthnum', 'day'), $redirect['query']);
 199                 } elseif ( is_month() && get_query_var('year') && !empty($_GET['monthnum']) ) {
 200                         if ( $redirect_url = get_month_link(get_query_var('year'), get_query_var('monthnum')) )
 201                                 $redirect['query'] = remove_query_arg(array('year', 'monthnum'), $redirect['query']);
 202                 } elseif ( is_year() && !empty($_GET['year']) ) {
 203                         if ( $redirect_url = get_year_link(get_query_var('year')) )
 204                                 $redirect['query'] = remove_query_arg('year', $redirect['query']);
 205                 } elseif ( is_author() && !empty($_GET['author']) && preg_match( '|^[0-9]+$|', $_GET['author'] ) ) {
 206                         $author = get_userdata(get_query_var('author'));
 207                         if ( ( false !== $author ) && $wpdb->get_var( $wpdb->prepare( "SELECT ID FROM $wpdb->posts WHERE $wpdb->posts.post_author = %d AND $wpdb->posts.post_status = 'publish' LIMIT 1", $author->ID ) ) ) {
 208                                 if ( $redirect_url = get_author_posts_url($author->ID, $author->user_nicename) )
 209                                         $redirect['query'] = remove_query_arg('author', $redirect['query']);
 210                         }
 211                 } elseif ( is_category() || is_tag() || is_tax() ) { // Terms (Tags/categories)
 212
 213                         $term_count = 0;
 214                         foreach ( $wp_query->tax_query->queried_terms as $tax_query )
 215                                 $term_count += count( $tax_query['terms'] );
 216
 217                         $obj = $wp_query->get_queried_object();
 218                         if ( $term_count <= 1 && !empty($obj->term_id) && ( $tax_url = get_term_link((int)$obj->term_id, $obj->taxonomy) ) && !is_wp_error($tax_url) ) {
 219                                 if ( !empty($redirect['query']) ) {
 220                                         // Strip taxonomy query vars off the url.
 221                                         $qv_remove = array( 'term', 'taxonomy');
 222                                         if ( is_category() ) {
 223                                                 $qv_remove[] = 'category_name';
 224                                                 $qv_remove[] = 'cat';
 225                                         } elseif ( is_tag() ) {
 226                                                 $qv_remove[] = 'tag';
 227                                                 $qv_remove[] = 'tag_id';
 228                                         } else { // Custom taxonomies will have a custom query var, remove those too:
 229                                                 $tax_obj = get_taxonomy( $obj->taxonomy );
 230                                                 if ( false !== $tax_obj->query_var )
 231                                                         $qv_remove[] = $tax_obj->query_var;
 232                                         }
 233
 234                                         $rewrite_vars = array_diff( array_keys($wp_query->query), array_keys($_GET) );
 235
 236                                         if ( !array_diff($rewrite_vars, array_keys($_GET))  ) { // Check to see if all the Query vars are coming from the rewrite, none are set via $_GET
 237                                                 $redirect['query'] = remove_query_arg($qv_remove, $redirect['query']); //Remove all of the per-tax qv's
 238
 239                                                 // Create the destination url for this taxonomy
 240                                                 $tax_url = parse_url($tax_url);
 241                                                 if ( ! empty($tax_url['query']) ) { // Taxonomy accessible via ?taxonomy=..&term=.. or any custom qv..
 242                                                         parse_str($tax_url['query'], $query_vars);
 243                                                         $redirect['query'] = add_query_arg($query_vars, $redirect['query']);
 244                                                 } else { // Taxonomy is accessible via a "pretty-URL"
 245                                                         $redirect['path'] = $tax_url['path'];
 246                                                 }
 247
 248                                         } else { // Some query vars are set via $_GET. Unset those from $_GET that exist via the rewrite
 249                                                 foreach ( $qv_remove as $_qv ) {
 250                                                         if ( isset($rewrite_vars[$_qv]) )
 251                                                                 $redirect['query'] = remove_query_arg($_qv, $redirect['query']);
 252                                                 }
 253                                         }
 254                                 }
 255
 256                         }
 257                 } elseif ( is_single() && strpos($wp_rewrite->permalink_structure, '%category%') !== false && $cat = get_query_var( 'category_name' ) ) {
 258                         $category = get_category_by_path( $cat );
 259                         if ( ( ! $category || is_wp_error( $category ) ) || ! has_term( $category->term_id, 'category', $wp_query->get_queried_object_id() ) ) {
 260                                 $redirect_url = get_permalink($wp_query->get_queried_object_id());
 261                         }
 262                 }
 263
 264                 // Post Paging
 265                 if ( is_singular() && get_query_var('page') ) {
 266                         if ( !$redirect_url )
 267                                 $redirect_url = get_permalink( get_queried_object_id() );
 268
 269                         $page = get_query_var( 'page' );
 270                         if ( $page > 1 ) {
 271                                 if ( is_front_page() ) {
 272                                         $redirect_url = trailingslashit( $redirect_url ) . user_trailingslashit( "$wp_rewrite->pagination_base/$page", 'paged' );
 273                                 } else {
 274                                         $redirect_url = trailingslashit( $redirect_url ) . user_trailingslashit( $page, 'single_paged' );
 275                                 }
 276                         }
 277                         $redirect['query'] = remove_query_arg( 'page', $redirect['query'] );
 278                 }
 279
 280                 // paging and feeds
 281                 if ( get_query_var('paged') || is_feed() || get_query_var('cpage') ) {
 282                         while ( preg_match( "#/$wp_rewrite->pagination_base/?[0-9]+?(/+)?$#", $redirect['path'] ) || preg_match( '#/(comments/?)?(feed|rss|rdf|atom|rss2)(/+)?$#', $redirect['path'] ) || preg_match( "#/{$wp_rewrite->comments_pagination_base}-[0-9]+(/+)?$#", $redirect['path'] ) ) {
 283                                 // Strip off paging and feed
 284                                 $redirect['path'] = preg_replace("#/$wp_rewrite->pagination_base/?[0-9]+?(/+)?$#", '/', $redirect['path']); // strip off any existing paging
 285                                 $redirect['path'] = preg_replace('#/(comments/?)?(feed|rss2?|rdf|atom)(/+|$)#', '/', $redirect['path']); // strip off feed endings
 286                                 $redirect['path'] = preg_replace("#/{$wp_rewrite->comments_pagination_base}-[0-9]+?(/+)?$#", '/', $redirect['path']); // strip off any existing comment paging
 287                         }
 288
 289                         $addl_path = '';
 290                         if ( is_feed() && in_array( get_query_var('feed'), $wp_rewrite->feeds ) ) {
 291                                 $addl_path = !empty( $addl_path ) ? trailingslashit($addl_path) : '';
 292                                 if ( !is_singular() && get_query_var( 'withcomments' ) )
 293                                         $addl_path .= 'comments/';
 294                                 if ( ( 'rss' == get_default_feed() && 'feed' == get_query_var('feed') ) || 'rss' == get_query_var('feed') )
 295                                         $addl_path .= user_trailingslashit( 'feed/' . ( ( get_default_feed() == 'rss2' ) ? '' : 'rss2' ), 'feed' );
 296                                 else
 297                                         $addl_path .= user_trailingslashit( 'feed/' . ( ( get_default_feed() ==  get_query_var('feed') || 'feed' == get_query_var('feed') ) ? '' : get_query_var('feed') ), 'feed' );
 298                                 $redirect['query'] = remove_query_arg( 'feed', $redirect['query'] );
 299                         } elseif ( is_feed() && 'old' == get_query_var('feed') ) {
 300                                 $old_feed_files = array(
 301                                         'wp-atom.php'         => 'atom',
 302                                         'wp-commentsrss2.php' => 'comments_rss2',
 303                                         'wp-feed.php'         => get_default_feed(),
 304                                         'wp-rdf.php'          => 'rdf',
 305                                         'wp-rss.php'          => 'rss2',
 306                                         'wp-rss2.php'         => 'rss2',
 307                                 );
 308                                 if ( isset( $old_feed_files[ basename( $redirect['path'] ) ] ) ) {
 309                                         $redirect_url = get_feed_link( $old_feed_files[ basename( $redirect['path'] ) ] );
 310                                         wp_redirect( $redirect_url, 301 );
 311                                         die();
 312                                 }
 313                         }
 314
 315                         if ( get_query_var('paged') > 0 ) {
 316                                 $paged = get_query_var('paged');
 317                                 $redirect['query'] = remove_query_arg( 'paged', $redirect['query'] );
 318                                 if ( !is_feed() ) {
 319                                         if ( $paged > 1 && !is_single() ) {
 320                                                 $addl_path = ( !empty( $addl_path ) ? trailingslashit($addl_path) : '' ) . user_trailingslashit("$wp_rewrite->pagination_base/$paged", 'paged');
 321                                         } elseif ( !is_single() ) {
 322                                                 $addl_path = !empty( $addl_path ) ? trailingslashit($addl_path) : '';
 323                                         }
 324                                 } elseif ( $paged > 1 ) {
 325                                         $redirect['query'] = add_query_arg( 'paged', $paged, $redirect['query'] );
 326                                 }
 327                         }
 328
 329                         if ( get_option( 'page_comments' ) && (
 330                                 ( 'newest' == get_option( 'default_comments_page' ) && get_query_var( 'cpage' ) > 0 ) ||
 331                                 ( 'newest' != get_option( 'default_comments_page' ) && get_query_var( 'cpage' ) > 1 )
 332                         ) ) {
 333                                 $addl_path = ( !empty( $addl_path ) ? trailingslashit($addl_path) : '' ) . user_trailingslashit( $wp_rewrite->comments_pagination_base . '-' . get_query_var('cpage'), 'commentpaged' );
 334                                 $redirect['query'] = remove_query_arg( 'cpage', $redirect['query'] );
 335                         }
 336
 337                         $redirect['path'] = user_trailingslashit( preg_replace('|/' . preg_quote( $wp_rewrite->index, '|' ) . '/?$|', '/', $redirect['path']) ); // strip off trailing /index.php/
 338                         if ( !empty( $addl_path ) && $wp_rewrite->using_index_permalinks() && strpos($redirect['path'], '/' . $wp_rewrite->index . '/') === false )
 339                                 $redirect['path'] = trailingslashit($redirect['path']) . $wp_rewrite->index . '/';
 340                         if ( !empty( $addl_path ) )
 341                                 $redirect['path'] = trailingslashit($redirect['path']) . $addl_path;
 342                         $redirect_url = $redirect['scheme'] . '://' . $redirect['host'] . $redirect['path'];
 343                 }
 344
 345                 if ( 'wp-register.php' == basename( $redirect['path'] ) ) {
 346                         if ( is_multisite() ) {
 347                                 /** This filter is documented in wp-login.php */
 348                                 $redirect_url = apply_filters( 'wp_signup_location', network_site_url( 'wp-signup.php' ) );
 349                         } else {
 350                                 $redirect_url = wp_registration_url();
 351                         }
 352
 353                         wp_redirect( $redirect_url, 301 );
 354                         die();
 355                 }
 356         }
 357
 358         // tack on any additional query vars
 359         $redirect['query'] = preg_replace( '#^\??&*?#', '', $redirect['query'] );
 360         if ( $redirect_url && !empty($redirect['query']) ) {
 361                 parse_str( $redirect['query'], $_parsed_query );
 362                 $redirect = @parse_url($redirect_url);
 363
 364                 if ( ! empty( $_parsed_query['name'] ) && ! empty( $redirect['query'] ) ) {
 365                         parse_str( $redirect['query'], $_parsed_redirect_query );
 366
 367                         if ( empty( $_parsed_redirect_query['name'] ) )
 368                                 unset( $_parsed_query['name'] );
 369                 }
 370
 371                 $_parsed_query = rawurlencode_deep( $_parsed_query );
 372                 $redirect_url = add_query_arg( $_parsed_query, $redirect_url );
 373         }
 374
 375         if ( $redirect_url )
 376                 $redirect = @parse_url($redirect_url);
 377
 378         // www.example.com vs example.com
 379         $user_home = @parse_url(home_url());
 380         if ( !empty($user_home['host']) )
 381                 $redirect['host'] = $user_home['host'];
 382         if ( empty($user_home['path']) )
 383                 $user_home['path'] = '/';
 384
 385         // Handle ports
 386         if ( !empty($user_home['port']) )
 387                 $redirect['port'] = $user_home['port'];
 388         else
 389                 unset($redirect['port']);
 390
 391         // trailing /index.php
 392         $redirect['path'] = preg_replace('|/' . preg_quote( $wp_rewrite->index, '|' ) . '/*?$|', '/', $redirect['path']);
 393
 394         // Remove trailing spaces from the path
 395         $redirect['path'] = preg_replace( '#(%20| )+$#', '', $redirect['path'] );
 396
 397         if ( !empty( $redirect['query'] ) ) {
 398                 // Remove trailing spaces from certain terminating query string args
 399                 $redirect['query'] = preg_replace( '#((p|page_id|cat|tag)=[^&]*?)(%20| )+$#', '$1', $redirect['query'] );
 400
 401                 // Clean up empty query strings
 402                 $redirect['query'] = trim(preg_replace( '#(^|&)(p|page_id|cat|tag)=?(&|$)#', '&', $redirect['query']), '&');
 403
 404                 // Redirect obsolete feeds
 405                 $redirect['query'] = preg_replace( '#(^|&)feed=rss(&|$)#', '$1feed=rss2$2', $redirect['query'] );
 406
 407                 // Remove redundant leading ampersands
 408                 $redirect['query'] = preg_replace( '#^\??&*?#', '', $redirect['query'] );
 409         }
 410
 411         // strip /index.php/ when we're not using PATHINFO permalinks
 412         if ( !$wp_rewrite->using_index_permalinks() )
 413                 $redirect['path'] = str_replace( '/' . $wp_rewrite->index . '/', '/', $redirect['path'] );
 414
 415         // trailing slashes
 416         if ( is_object($wp_rewrite) && $wp_rewrite->using_permalinks() && !is_404() && (!is_front_page() || ( is_front_page() && (get_query_var('paged') > 1) ) ) ) {
 417                 $user_ts_type = '';
 418                 if ( get_query_var('paged') > 0 ) {
 419                         $user_ts_type = 'paged';
 420                 } else {
 421                         foreach ( array('single', 'category', 'page', 'day', 'month', 'year', 'home') as $type ) {
 422                                 $func = 'is_' . $type;
 423                                 if ( call_user_func($func) ) {
 424                                         $user_ts_type = $type;
 425                                         break;
 426                                 }
 427                         }
 428                 }
 429                 $redirect['path'] = user_trailingslashit($redirect['path'], $user_ts_type);
 430         } elseif ( is_front_page() ) {
 431                 $redirect['path'] = trailingslashit($redirect['path']);
 432         }
 433
 434         // Strip multiple slashes out of the URL
 435         if ( strpos($redirect['path'], '//') > -1 )
 436                 $redirect['path'] = preg_replace('|/+|', '/', $redirect['path']);
 437
 438         // Always trailing slash the Front Page URL
 439         if ( trailingslashit( $redirect['path'] ) == trailingslashit( $user_home['path'] ) )
 440                 $redirect['path'] = trailingslashit($redirect['path']);
 441
 442         // Ignore differences in host capitalization, as this can lead to infinite redirects
 443         // Only redirect no-www <=> yes-www
 444         if ( strtolower($original['host']) == strtolower($redirect['host']) ||
 445                 ( strtolower($original['host']) != 'www.' . strtolower($redirect['host']) && 'www.' . strtolower($original['host']) != strtolower($redirect['host']) ) )
 446                 $redirect['host'] = $original['host'];
 447
 448         $compare_original = array( $original['host'], $original['path'] );
 449
 450         if ( !empty( $original['port'] ) )
 451                 $compare_original[] = $original['port'];
 452
 453         if ( !empty( $original['query'] ) )
 454                 $compare_original[] = $original['query'];
 455
 456         $compare_redirect = array( $redirect['host'], $redirect['path'] );
 457
 458         if ( !empty( $redirect['port'] ) )
 459                 $compare_redirect[] = $redirect['port'];
 460
 461         if ( !empty( $redirect['query'] ) )
 462                 $compare_redirect[] = $redirect['query'];
 463
 464         if ( $compare_original !== $compare_redirect ) {
 465                 $redirect_url = $redirect['scheme'] . '://' . $redirect['host'];
 466                 if ( !empty($redirect['port']) )
 467                         $redirect_url .= ':' . $redirect['port'];
 468                 $redirect_url .= $redirect['path'];
 469                 if ( !empty($redirect['query']) )
 470                         $redirect_url .= '?' . $redirect['query'];
 471         }
 472
 473         if ( ! $redirect_url || $redirect_url == $requested_url ) {
 474                 return;
 475         }
 476
 477         // Hex encoded octets are case-insensitive.
 478         if ( false !== strpos($requested_url, '%') ) {
 479                 if ( !function_exists('lowercase_octets') ) {
 480                         /**
 481                          * Converts the first hex-encoded octet match to lowercase.
 482                          *
 483                          * @since 3.1.0
 484                          * @ignore
 485                          *
 486                          * @param array $matches Hex-encoded octet matches for the requested URL.
 487                          * @return string Lowercased version of the first match.
 488                          */
 489                         function lowercase_octets($matches) {
 490                                 return strtolower( $matches[0] );
 491                         }
 492                 }
 493                 $requested_url = preg_replace_callback('|%[a-fA-F0-9][a-fA-F0-9]|', 'lowercase_octets', $requested_url);
 494         }
 495
 496         /**
 497          * Filters the canonical redirect URL.
 498          *
 499          * Returning false to this filter will cancel the redirect.
 500          *
 501          * @since 2.3.0
 502          *
 503          * @param string $redirect_url  The redirect URL.
 504          * @param string $requested_url The requested URL.
 505          */
 506         $redirect_url = apply_filters( 'redirect_canonical', $redirect_url, $requested_url );
 507
 508         // yes, again -- in case the filter aborted the request
 509         if ( ! $redirect_url || strip_fragment_from_url( $redirect_url ) == strip_fragment_from_url( $requested_url ) ) {
 510                 return;
 511         }
 512
 513         if ( $do_redirect ) {
 514                 // protect against chained redirects
 515                 if ( !redirect_canonical($redirect_url, false) ) {
 516                         wp_redirect($redirect_url, 301);
 517                         exit();
 518                 } else {
 519                         // Debug
 520                         // die("1: $redirect_url<br />2: " . redirect_canonical( $redirect_url, false ) );
 521                         return;
 522                 }
 523         } else {
 524                 return $redirect_url;
 525         }
 526 }
 527
 528 /**
 529  * Removes arguments from a query string if they are not present in a URL
 530  * DO NOT use this in plugin code.
 531  *
 532  * @since 3.4.0
 533  * @access private
 534  *
 535  * @param string $query_string
 536  * @param array $args_to_check
 537  * @param string $url
 538  * @return string The altered query string
 539  */
 540 function _remove_qs_args_if_not_in_url( $query_string, Array $args_to_check, $url ) {
 541         $parsed_url = @parse_url( $url );
 542         if ( ! empty( $parsed_url['query'] ) ) {
 543                 parse_str( $parsed_url['query'], $parsed_query );
 544                 foreach ( $args_to_check as $qv ) {
 545                         if ( !isset( $parsed_query[$qv] ) )
 546                                 $query_string = remove_query_arg( $qv, $query_string );
 547                 }
 548         } else {
 549                 $query_string = remove_query_arg( $args_to_check, $query_string );
 550         }
 551         return $query_string;
 552 }
 553
 554 /**
 555  * Strips the #fragment from a URL, if one is present.
 556  *
 557  * @since 4.4.0
 558  *
 559  * @param string $url The URL to strip.
 560  * @return string The altered URL.
 561  */
 562 function strip_fragment_from_url( $url ) {
 563         $parsed_url = @parse_url( $url );
 564         if ( ! empty( $parsed_url['host'] ) ) {
 565                 // This mirrors code in redirect_canonical(). It does not handle every case.
 566                 $url = $parsed_url['scheme'] . '://' . $parsed_url['host'];
 567                 if ( ! empty( $parsed_url['port'] ) ) {
 568                         $url .= ':' . $parsed_url['port'];
 569                 }
 570                 $url .= $parsed_url['path'];
 571                 if ( ! empty( $parsed_url['query'] ) ) {
 572                         $url .= '?' . $parsed_url['query'];
 573                 }
 574         }
 575
 576         return $url;
 577 }
 578
 579 /**
 580  * Attempts to guess the correct URL based on query vars
 581  *
 582  * @since 2.3.0
 583  *
 584  * @global wpdb $wpdb WordPress database abstraction object.
 585  *
 586  * @return false|string The correct URL if one is found. False on failure.
 587  */
 588 function redirect_guess_404_permalink() {
 589         global $wpdb;
 590
 591         if ( get_query_var('name') ) {
 592                 $where = $wpdb->prepare("post_name LIKE %s", $wpdb->esc_like( get_query_var('name') ) . '%');
 593
 594                 // if any of post_type, year, monthnum, or day are set, use them to refine the query
 595                 if ( get_query_var('post_type') )
 596                         $where .= $wpdb->prepare(" AND post_type = %s", get_query_var('post_type'));
 597                 else
 598                         $where .= " AND post_type IN ('" . implode( "', '", get_post_types( array( 'public' => true ) ) ) . "')";
 599
 600                 if ( get_query_var('year') )
 601                         $where .= $wpdb->prepare(" AND YEAR(post_date) = %d", get_query_var('year'));
 602                 if ( get_query_var('monthnum') )
 603                         $where .= $wpdb->prepare(" AND MONTH(post_date) = %d", get_query_var('monthnum'));
 604                 if ( get_query_var('day') )
 605                         $where .= $wpdb->prepare(" AND DAYOFMONTH(post_date) = %d", get_query_var('day'));
 606
 607                 $post_id = $wpdb->get_var("SELECT ID FROM $wpdb->posts WHERE $where AND post_status = 'publish'");
 608                 if ( ! $post_id )
 609                         return false;
 610                 if ( get_query_var( 'feed' ) )
 611                         return get_post_comments_feed_link( $post_id, get_query_var( 'feed' ) );
 612                 elseif ( get_query_var( 'page' ) && 1 < get_query_var( 'page' ) )
 613                         return trailingslashit( get_permalink( $post_id ) ) . user_trailingslashit( get_query_var( 'page' ), 'single_paged' );
 614                 else
 615                         return get_permalink( $post_id );
 616         }
 617
 618         return false;
 619 }
 620
 621 /**
 622  * Redirects a variety of shorthand URLs to the admin.
 623  *
 624  * If a user visits example.com/admin, they'll be redirected to /wp-admin.
 625  * Visiting /login redirects to /wp-login.php, and so on.
 626  *
 627  * @since 3.4.0
 628  *
 629  * @global WP_Rewrite $wp_rewrite
 630  */
 631 function wp_redirect_admin_locations() {
 632         global $wp_rewrite;
 633         if ( ! ( is_404() && $wp_rewrite->using_permalinks() ) )
 634                 return;
 635
 636         $admins = array(
 637                 home_url( 'wp-admin', 'relative' ),
 638                 home_url( 'dashboard', 'relative' ),
 639                 home_url( 'admin', 'relative' ),
 640                 site_url( 'dashboard', 'relative' ),
 641                 site_url( 'admin', 'relative' ),
 642         );
 643         if ( in_array( untrailingslashit( $_SERVER['REQUEST_URI'] ), $admins ) ) {
 644                 wp_redirect( admin_url() );
 645                 exit;
 646         }
 647
 648         $logins = array(
 649                 home_url( 'wp-login.php', 'relative' ),
 650                 home_url( 'login', 'relative' ),
 651                 site_url( 'login', 'relative' ),
 652         );
 653         if ( in_array( untrailingslashit( $_SERVER['REQUEST_URI'] ), $logins ) ) {
 654                 wp_redirect( wp_login_url() );
 655                 exit;
 656         }
 657 }