WordPress 4.4
[autoinstalls/wordpress.git] / 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, comment popup, 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_comments_popup() || 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', $redirect['query']);
175                 } elseif ( is_page() && !is_feed() && isset($wp_query->queried_object) && 'page' == get_option('show_on_front') && $wp_query->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                         $post_terms = wp_get_object_terms($wp_query->get_queried_object_id(), 'category', array('fields' => 'tt_ids'));
260                         if ( (!$category || is_wp_error($category)) || ( !is_wp_error($post_terms) && !empty($post_terms) && !in_array($category->term_taxonomy_id, $post_terms) ) )
261                                 $redirect_url = get_permalink($wp_query->get_queried_object_id());
262                 }
263
264                 // Post Paging
265                 if ( is_singular() && ! is_front_page() && get_query_var('page') ) {
266                         if ( !$redirect_url )
267                                 $redirect_url = get_permalink( get_queried_object_id() );
268                         $redirect_url = trailingslashit( $redirect_url ) . user_trailingslashit( get_query_var( 'page' ), 'single_paged' );
269                         $redirect['query'] = remove_query_arg( 'page', $redirect['query'] );
270                 }
271
272                 // paging and feeds
273                 if ( get_query_var('paged') || is_feed() || get_query_var('cpage') ) {
274                         while ( preg_match( "#/$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'] ) ) {
275                                 // Strip off paging and feed
276                                 $redirect['path'] = preg_replace("#/$wp_rewrite->pagination_base/?[0-9]+?(/+)?$#", '/', $redirect['path']); // strip off any existing paging
277                                 $redirect['path'] = preg_replace('#/(comments/?)?(feed|rss2?|rdf|atom)(/+|$)#', '/', $redirect['path']); // strip off feed endings
278                                 $redirect['path'] = preg_replace("#/{$wp_rewrite->comments_pagination_base}-[0-9]+?(/+)?$#", '/', $redirect['path']); // strip off any existing comment paging
279                         }
280
281                         $addl_path = '';
282                         if ( is_feed() && in_array( get_query_var('feed'), $wp_rewrite->feeds ) ) {
283                                 $addl_path = !empty( $addl_path ) ? trailingslashit($addl_path) : '';
284                                 if ( !is_singular() && get_query_var( 'withcomments' ) )
285                                         $addl_path .= 'comments/';
286                                 if ( ( 'rss' == get_default_feed() && 'feed' == get_query_var('feed') ) || 'rss' == get_query_var('feed') )
287                                         $addl_path .= user_trailingslashit( 'feed/' . ( ( get_default_feed() == 'rss2' ) ? '' : 'rss2' ), 'feed' );
288                                 else
289                                         $addl_path .= user_trailingslashit( 'feed/' . ( ( get_default_feed() ==  get_query_var('feed') || 'feed' == get_query_var('feed') ) ? '' : get_query_var('feed') ), 'feed' );
290                                 $redirect['query'] = remove_query_arg( 'feed', $redirect['query'] );
291                         } elseif ( is_feed() && 'old' == get_query_var('feed') ) {
292                                 $old_feed_files = array(
293                                         'wp-atom.php'         => 'atom',
294                                         'wp-commentsrss2.php' => 'comments_rss2',
295                                         'wp-feed.php'         => get_default_feed(),
296                                         'wp-rdf.php'          => 'rdf',
297                                         'wp-rss.php'          => 'rss2',
298                                         'wp-rss2.php'         => 'rss2',
299                                 );
300                                 if ( isset( $old_feed_files[ basename( $redirect['path'] ) ] ) ) {
301                                         $redirect_url = get_feed_link( $old_feed_files[ basename( $redirect['path'] ) ] );
302                                         wp_redirect( $redirect_url, 301 );
303                                         die();
304                                 }
305                         }
306
307                         if ( get_query_var('paged') > 0 ) {
308                                 $paged = get_query_var('paged');
309                                 $redirect['query'] = remove_query_arg( 'paged', $redirect['query'] );
310                                 if ( !is_feed() ) {
311                                         if ( $paged > 1 && !is_single() ) {
312                                                 $addl_path = ( !empty( $addl_path ) ? trailingslashit($addl_path) : '' ) . user_trailingslashit("$wp_rewrite->pagination_base/$paged", 'paged');
313                                         } elseif ( !is_single() ) {
314                                                 $addl_path = !empty( $addl_path ) ? trailingslashit($addl_path) : '';
315                                         }
316                                 } elseif ( $paged > 1 ) {
317                                         $redirect['query'] = add_query_arg( 'paged', $paged, $redirect['query'] );
318                                 }
319                         }
320
321                         if ( get_option( 'page_comments' ) && (
322                                 ( 'newest' == get_option( 'default_comments_page' ) && get_query_var( 'cpage' ) > 0 ) ||
323                                 ( 'newest' != get_option( 'default_comments_page' ) && get_query_var( 'cpage' ) > 1 )
324                         ) ) {
325                                 $addl_path = ( !empty( $addl_path ) ? trailingslashit($addl_path) : '' ) . user_trailingslashit( $wp_rewrite->comments_pagination_base . '-' . get_query_var('cpage'), 'commentpaged' );
326                                 $redirect['query'] = remove_query_arg( 'cpage', $redirect['query'] );
327                         }
328
329                         $redirect['path'] = user_trailingslashit( preg_replace('|/' . preg_quote( $wp_rewrite->index, '|' ) . '/?$|', '/', $redirect['path']) ); // strip off trailing /index.php/
330                         if ( !empty( $addl_path ) && $wp_rewrite->using_index_permalinks() && strpos($redirect['path'], '/' . $wp_rewrite->index . '/') === false )
331                                 $redirect['path'] = trailingslashit($redirect['path']) . $wp_rewrite->index . '/';
332                         if ( !empty( $addl_path ) )
333                                 $redirect['path'] = trailingslashit($redirect['path']) . $addl_path;
334                         $redirect_url = $redirect['scheme'] . '://' . $redirect['host'] . $redirect['path'];
335                 }
336
337                 if ( 'wp-register.php' == basename( $redirect['path'] ) ) {
338                         if ( is_multisite() ) {
339                                 /** This filter is documented in wp-login.php */
340                                 $redirect_url = apply_filters( 'wp_signup_location', network_site_url( 'wp-signup.php' ) );
341                         } else {
342                                 $redirect_url = wp_registration_url();
343                         }
344
345                         wp_redirect( $redirect_url, 301 );
346                         die();
347                 }
348         }
349
350         // tack on any additional query vars
351         $redirect['query'] = preg_replace( '#^\??&*?#', '', $redirect['query'] );
352         if ( $redirect_url && !empty($redirect['query']) ) {
353                 parse_str( $redirect['query'], $_parsed_query );
354                 $redirect = @parse_url($redirect_url);
355
356                 if ( ! empty( $_parsed_query['name'] ) && ! empty( $redirect['query'] ) ) {
357                         parse_str( $redirect['query'], $_parsed_redirect_query );
358
359                         if ( empty( $_parsed_redirect_query['name'] ) )
360                                 unset( $_parsed_query['name'] );
361                 }
362
363                 $_parsed_query = rawurlencode_deep( $_parsed_query );
364                 $redirect_url = add_query_arg( $_parsed_query, $redirect_url );
365         }
366
367         if ( $redirect_url )
368                 $redirect = @parse_url($redirect_url);
369
370         // www.example.com vs example.com
371         $user_home = @parse_url(home_url());
372         if ( !empty($user_home['host']) )
373                 $redirect['host'] = $user_home['host'];
374         if ( empty($user_home['path']) )
375                 $user_home['path'] = '/';
376
377         // Handle ports
378         if ( !empty($user_home['port']) )
379                 $redirect['port'] = $user_home['port'];
380         else
381                 unset($redirect['port']);
382
383         // trailing /index.php
384         $redirect['path'] = preg_replace('|/' . preg_quote( $wp_rewrite->index, '|' ) . '/*?$|', '/', $redirect['path']);
385
386         // Remove trailing spaces from the path
387         $redirect['path'] = preg_replace( '#(%20| )+$#', '', $redirect['path'] );
388
389         if ( !empty( $redirect['query'] ) ) {
390                 // Remove trailing spaces from certain terminating query string args
391                 $redirect['query'] = preg_replace( '#((p|page_id|cat|tag)=[^&]*?)(%20| )+$#', '$1', $redirect['query'] );
392
393                 // Clean up empty query strings
394                 $redirect['query'] = trim(preg_replace( '#(^|&)(p|page_id|cat|tag)=?(&|$)#', '&', $redirect['query']), '&');
395
396                 // Redirect obsolete feeds
397                 $redirect['query'] = preg_replace( '#(^|&)feed=rss(&|$)#', '$1feed=rss2$2', $redirect['query'] );
398
399                 // Remove redundant leading ampersands
400                 $redirect['query'] = preg_replace( '#^\??&*?#', '', $redirect['query'] );
401         }
402
403         // strip /index.php/ when we're not using PATHINFO permalinks
404         if ( !$wp_rewrite->using_index_permalinks() )
405                 $redirect['path'] = str_replace( '/' . $wp_rewrite->index . '/', '/', $redirect['path'] );
406
407         // trailing slashes
408         if ( is_object($wp_rewrite) && $wp_rewrite->using_permalinks() && !is_404() && (!is_front_page() || ( is_front_page() && (get_query_var('paged') > 1) ) ) ) {
409                 $user_ts_type = '';
410                 if ( get_query_var('paged') > 0 ) {
411                         $user_ts_type = 'paged';
412                 } else {
413                         foreach ( array('single', 'category', 'page', 'day', 'month', 'year', 'home') as $type ) {
414                                 $func = 'is_' . $type;
415                                 if ( call_user_func($func) ) {
416                                         $user_ts_type = $type;
417                                         break;
418                                 }
419                         }
420                 }
421                 $redirect['path'] = user_trailingslashit($redirect['path'], $user_ts_type);
422         } elseif ( is_front_page() ) {
423                 $redirect['path'] = trailingslashit($redirect['path']);
424         }
425
426         // Strip multiple slashes out of the URL
427         if ( strpos($redirect['path'], '//') > -1 )
428                 $redirect['path'] = preg_replace('|/+|', '/', $redirect['path']);
429
430         // Always trailing slash the Front Page URL
431         if ( trailingslashit( $redirect['path'] ) == trailingslashit( $user_home['path'] ) )
432                 $redirect['path'] = trailingslashit($redirect['path']);
433
434         // Ignore differences in host capitalization, as this can lead to infinite redirects
435         // Only redirect no-www <=> yes-www
436         if ( strtolower($original['host']) == strtolower($redirect['host']) ||
437                 ( strtolower($original['host']) != 'www.' . strtolower($redirect['host']) && 'www.' . strtolower($original['host']) != strtolower($redirect['host']) ) )
438                 $redirect['host'] = $original['host'];
439
440         $compare_original = array( $original['host'], $original['path'] );
441
442         if ( !empty( $original['port'] ) )
443                 $compare_original[] = $original['port'];
444
445         if ( !empty( $original['query'] ) )
446                 $compare_original[] = $original['query'];
447
448         $compare_redirect = array( $redirect['host'], $redirect['path'] );
449
450         if ( !empty( $redirect['port'] ) )
451                 $compare_redirect[] = $redirect['port'];
452
453         if ( !empty( $redirect['query'] ) )
454                 $compare_redirect[] = $redirect['query'];
455
456         if ( $compare_original !== $compare_redirect ) {
457                 $redirect_url = $redirect['scheme'] . '://' . $redirect['host'];
458                 if ( !empty($redirect['port']) )
459                         $redirect_url .= ':' . $redirect['port'];
460                 $redirect_url .= $redirect['path'];
461                 if ( !empty($redirect['query']) )
462                         $redirect_url .= '?' . $redirect['query'];
463         }
464
465         if ( ! $redirect_url || $redirect_url == $requested_url ) {
466                 return;
467         }
468
469         // Hex encoded octets are case-insensitive.
470         if ( false !== strpos($requested_url, '%') ) {
471                 if ( !function_exists('lowercase_octets') ) {
472                         function lowercase_octets($matches) {
473                                 return strtolower( $matches[0] );
474                         }
475                 }
476                 $requested_url = preg_replace_callback('|%[a-fA-F0-9][a-fA-F0-9]|', 'lowercase_octets', $requested_url);
477         }
478
479         /**
480          * Filter the canonical redirect URL.
481          *
482          * Returning false to this filter will cancel the redirect.
483          *
484          * @since 2.3.0
485          *
486          * @param string $redirect_url  The redirect URL.
487          * @param string $requested_url The requested URL.
488          */
489         $redirect_url = apply_filters( 'redirect_canonical', $redirect_url, $requested_url );
490
491         // yes, again -- in case the filter aborted the request
492         if ( ! $redirect_url || strip_fragment_from_url( $redirect_url ) == strip_fragment_from_url( $requested_url ) ) {
493                 return;
494         }
495
496         if ( $do_redirect ) {
497                 // protect against chained redirects
498                 if ( !redirect_canonical($redirect_url, false) ) {
499                         wp_redirect($redirect_url, 301);
500                         exit();
501                 } else {
502                         // Debug
503                         // die("1: $redirect_url<br />2: " . redirect_canonical( $redirect_url, false ) );
504                         return;
505                 }
506         } else {
507                 return $redirect_url;
508         }
509 }
510
511 /**
512  * Removes arguments from a query string if they are not present in a URL
513  * DO NOT use this in plugin code.
514  *
515  * @since 3.4.0
516  * @access private
517  *
518  * @param string $query_string
519  * @param array $args_to_check
520  * @param string $url
521  * @return string The altered query string
522  */
523 function _remove_qs_args_if_not_in_url( $query_string, Array $args_to_check, $url ) {
524         $parsed_url = @parse_url( $url );
525         if ( ! empty( $parsed_url['query'] ) ) {
526                 parse_str( $parsed_url['query'], $parsed_query );
527                 foreach ( $args_to_check as $qv ) {
528                         if ( !isset( $parsed_query[$qv] ) )
529                                 $query_string = remove_query_arg( $qv, $query_string );
530                 }
531         } else {
532                 $query_string = remove_query_arg( $args_to_check, $query_string );
533         }
534         return $query_string;
535 }
536
537 /**
538  * Strips the #fragment from a URL, if one is present.
539  *
540  * @since 4.4.0
541  *
542  * @param string $url The URL to strip.
543  * @return string The altered URL.
544  */
545 function strip_fragment_from_url( $url ) {
546         $parsed_url = @parse_url( $url );
547         if ( ! empty( $parsed_url['host'] ) ) {
548                 // This mirrors code in redirect_canonical(). It does not handle every case.
549                 $url = $parsed_url['scheme'] . '://' . $parsed_url['host'];
550                 if ( ! empty( $parsed_url['port'] ) ) {
551                         $url .= ':' . $parsed_url['port'];
552                 }
553                 $url .= $parsed_url['path'];
554                 if ( ! empty( $parsed_url['query'] ) ) {
555                         $url .= '?' . $parsed_url['query'];
556                 }
557         }
558
559         return $url;
560 }
561
562 /**
563  * Attempts to guess the correct URL based on query vars
564  *
565  * @since 2.3.0
566  *
567  * @global wpdb $wpdb WordPress database abstraction object.
568  *
569  * @return false|string The correct URL if one is found. False on failure.
570  */
571 function redirect_guess_404_permalink() {
572         global $wpdb;
573
574         if ( get_query_var('name') ) {
575                 $where = $wpdb->prepare("post_name LIKE %s", $wpdb->esc_like( get_query_var('name') ) . '%');
576
577                 // if any of post_type, year, monthnum, or day are set, use them to refine the query
578                 if ( get_query_var('post_type') )
579                         $where .= $wpdb->prepare(" AND post_type = %s", get_query_var('post_type'));
580                 else
581                         $where .= " AND post_type IN ('" . implode( "', '", get_post_types( array( 'public' => true ) ) ) . "')";
582
583                 if ( get_query_var('year') )
584                         $where .= $wpdb->prepare(" AND YEAR(post_date) = %d", get_query_var('year'));
585                 if ( get_query_var('monthnum') )
586                         $where .= $wpdb->prepare(" AND MONTH(post_date) = %d", get_query_var('monthnum'));
587                 if ( get_query_var('day') )
588                         $where .= $wpdb->prepare(" AND DAYOFMONTH(post_date) = %d", get_query_var('day'));
589
590                 $post_id = $wpdb->get_var("SELECT ID FROM $wpdb->posts WHERE $where AND post_status = 'publish'");
591                 if ( ! $post_id )
592                         return false;
593                 if ( get_query_var( 'feed' ) )
594                         return get_post_comments_feed_link( $post_id, get_query_var( 'feed' ) );
595                 elseif ( get_query_var( 'page' ) && 1 < get_query_var( 'page' ) )
596                         return trailingslashit( get_permalink( $post_id ) ) . user_trailingslashit( get_query_var( 'page' ), 'single_paged' );
597                 else
598                         return get_permalink( $post_id );
599         }
600
601         return false;
602 }
603
604 /**
605  *
606  * @global WP_Rewrite $wp_rewrite
607  */
608 function wp_redirect_admin_locations() {
609         global $wp_rewrite;
610         if ( ! ( is_404() && $wp_rewrite->using_permalinks() ) )
611                 return;
612
613         $admins = array(
614                 home_url( 'wp-admin', 'relative' ),
615                 home_url( 'dashboard', 'relative' ),
616                 home_url( 'admin', 'relative' ),
617                 site_url( 'dashboard', 'relative' ),
618                 site_url( 'admin', 'relative' ),
619         );
620         if ( in_array( untrailingslashit( $_SERVER['REQUEST_URI'] ), $admins ) ) {
621                 wp_redirect( admin_url() );
622                 exit;
623         }
624
625         $logins = array(
626                 home_url( 'wp-login.php', 'relative' ),
627                 home_url( 'login', 'relative' ),
628                 site_url( 'login', 'relative' ),
629         );
630         if ( in_array( untrailingslashit( $_SERVER['REQUEST_URI'] ), $logins ) ) {
631                 wp_redirect( wp_login_url() );
632                 exit;
633         }
634 }