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1 <?php |
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2 /** |
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3 * Canonical API to handle WordPress Redirecting |
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4 * |
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5 * Based on "Permalink Redirect" from Scott Yang and "Enforce www. Preference" |
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6 * by Mark Jaquith |
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7 * |
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8 * @author Scott Yang |
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9 * @author Mark Jaquith |
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10 * @package WordPress |
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11 * @since 2.3.0 |
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12 */ |
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13 |
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14 /** |
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15 * Redirects incoming links to the proper URL based on the site url. |
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16 * |
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17 * Search engines consider www.somedomain.com and somedomain.com to be two |
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18 * different URLs when they both go to the same location. This SEO enhancement |
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19 * prevents penality for duplicate content by redirecting all incoming links to |
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20 * one or the other. |
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21 * |
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22 * Prevents redirection for feeds, trackbacks, searches, comment popup, and |
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23 * admin URLs. Does not redirect on IIS, page/post previews, and on form data. |
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24 * |
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25 * Will also attempt to find the correct link when a user enters a URL that does |
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26 * not exist based on exact WordPress query. Will instead try to parse the URL |
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27 * or query in an attempt to figure the correct page to go to. |
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28 * |
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29 * @since 2.3.0 |
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30 * @uses $wp_rewrite |
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31 * @uses $is_IIS |
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32 * |
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33 * @param string $requested_url Optional. The URL that was requested, used to |
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34 * figure if redirect is needed. |
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35 * @param bool $do_redirect Optional. Redirect to the new URL. |
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36 * @return null|false|string Null, if redirect not needed. False, if redirect |
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37 * not needed or the string of the URL |
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38 */ |
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39 function redirect_canonical($requested_url=null, $do_redirect=true) { |
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40 global $wp_rewrite, $is_IIS, $wp_query, $wpdb; |
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41 |
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42 if ( is_trackback() || is_search() || is_comments_popup() || is_admin() || $is_IIS || ( isset($_POST) && count($_POST) ) || is_preview() || is_robots() ) |
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43 return; |
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44 |
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45 if ( !$requested_url ) { |
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46 // build the URL in the address bar |
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47 $requested_url = ( !empty($_SERVER['HTTPS'] ) && strtolower($_SERVER['HTTPS']) == 'on' ) ? 'https://' : 'http://'; |
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48 $requested_url .= $_SERVER['HTTP_HOST']; |
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49 $requested_url .= $_SERVER['REQUEST_URI']; |
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50 } |
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51 |
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52 $original = @parse_url($requested_url); |
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53 if ( false === $original ) |
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54 return; |
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55 |
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56 // Some PHP setups turn requests for / into /index.php in REQUEST_URI |
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57 // See: http://trac.wordpress.org/ticket/5017 |
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58 // See: http://trac.wordpress.org/ticket/7173 |
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59 // Disabled, for now: |
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60 // $original['path'] = preg_replace('|/index\.php$|', '/', $original['path']); |
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61 |
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62 $redirect = $original; |
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63 $redirect_url = false; |
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64 |
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65 // Notice fixing |
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66 if ( !isset($redirect['path']) ) $redirect['path'] = ''; |
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67 if ( !isset($redirect['query']) ) $redirect['query'] = ''; |
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68 |
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69 if ( is_singular() && 1 > $wp_query->post_count && ($id = get_query_var('p')) ) { |
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70 |
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71 $vars = $wpdb->get_results( $wpdb->prepare("SELECT post_type, post_parent FROM $wpdb->posts WHERE ID = %d", $id) ); |
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72 |
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73 if ( isset($vars[0]) && $vars = $vars[0] ) { |
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74 if ( 'revision' == $vars->post_type && $vars->post_parent > 0 ) |
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75 $id = $vars->post_parent; |
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76 |
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77 if ( $redirect_url = get_permalink($id) ) |
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78 $redirect['query'] = remove_query_arg(array('p', 'page_id', 'attachment_id'), $redirect['query']); |
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79 } |
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80 } |
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81 |
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82 // These tests give us a WP-generated permalink |
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83 if ( is_404() ) { |
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84 $redirect_url = redirect_guess_404_permalink(); |
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85 } elseif ( is_object($wp_rewrite) && $wp_rewrite->using_permalinks() ) { |
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86 // rewriting of old ?p=X, ?m=2004, ?m=200401, ?m=20040101 |
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87 if ( is_single() && !empty($_GET['p']) && ! $redirect_url ) { |
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88 if ( $redirect_url = get_permalink(get_query_var('p')) ) |
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89 $redirect['query'] = remove_query_arg('p', $redirect['query']); |
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90 if ( get_query_var( 'page' ) ) { |
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91 $redirect_url = trailingslashit( $redirect_url ) . user_trailingslashit( get_query_var( 'page' ), 'single_paged' ); |
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92 $redirect['query'] = remove_query_arg( 'page', $redirect['query'] ); |
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93 } |
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94 } elseif ( is_page() && !empty($_GET['page_id']) && ! $redirect_url ) { |
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95 if ( $redirect_url = get_permalink(get_query_var('page_id')) ) |
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96 $redirect['query'] = remove_query_arg('page_id', $redirect['query']); |
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97 } elseif ( !empty($_GET['m']) && ( is_year() || is_month() || is_day() ) ) { |
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98 $m = get_query_var('m'); |
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99 switch ( strlen($m) ) { |
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100 case 4: // Yearly |
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101 $redirect_url = get_year_link($m); |
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102 break; |
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103 case 6: // Monthly |
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104 $redirect_url = get_month_link( substr($m, 0, 4), substr($m, 4, 2) ); |
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105 break; |
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106 case 8: // Daily |
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107 $redirect_url = get_day_link(substr($m, 0, 4), substr($m, 4, 2), substr($m, 6, 2)); |
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108 break; |
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109 } |
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110 if ( $redirect_url ) |
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111 $redirect['query'] = remove_query_arg('m', $redirect['query']); |
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112 // now moving on to non ?m=X year/month/day links |
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113 } elseif ( is_day() && get_query_var('year') && get_query_var('monthnum') && !empty($_GET['day']) ) { |
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114 if ( $redirect_url = get_day_link(get_query_var('year'), get_query_var('monthnum'), get_query_var('day')) ) |
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115 $redirect['query'] = remove_query_arg(array('year', 'monthnum', 'day'), $redirect['query']); |
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116 } elseif ( is_month() && get_query_var('year') && !empty($_GET['monthnum']) ) { |
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117 if ( $redirect_url = get_month_link(get_query_var('year'), get_query_var('monthnum')) ) |
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118 $redirect['query'] = remove_query_arg(array('year', 'monthnum'), $redirect['query']); |
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119 } elseif ( is_year() && !empty($_GET['year']) ) { |
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120 if ( $redirect_url = get_year_link(get_query_var('year')) ) |
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121 $redirect['query'] = remove_query_arg('year', $redirect['query']); |
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122 } elseif ( is_category() && !empty($_GET['cat']) && preg_match( '|^[0-9]+$|', $_GET['cat'] ) ) { |
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123 if ( $redirect_url = get_category_link(get_query_var('cat')) ) |
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124 $redirect['query'] = remove_query_arg('cat', $redirect['query']); |
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125 } elseif ( is_author() && !empty($_GET['author']) ) { |
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126 $author = get_userdata(get_query_var('author')); |
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127 if ( false !== $author && $redirect_url = get_author_posts_url($author->ID, $author->user_nicename) ) |
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128 $redirect['query'] = remove_query_arg('author', $redirect['author']); |
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129 } |
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130 |
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131 // paging and feeds |
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132 if ( get_query_var('paged') || is_feed() || get_query_var('cpage') ) { |
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133 if ( !$redirect_url ) |
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134 $redirect_url = $requested_url; |
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135 $paged_redirect = @parse_url($redirect_url); |
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136 while ( preg_match( '#/page/[0-9]+?(/+)?$#', $paged_redirect['path'] ) || preg_match( '#/(comments/?)?(feed|rss|rdf|atom|rss2)(/+)?$#', $paged_redirect['path'] ) || preg_match( '#/comment-page-[0-9]+(/+)?$#', $paged_redirect['path'] ) ) { |
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137 // Strip off paging and feed |
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138 $paged_redirect['path'] = preg_replace('#/page/[0-9]+?(/+)?$#', '/', $paged_redirect['path']); // strip off any existing paging |
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139 $paged_redirect['path'] = preg_replace('#/(comments/?)?(feed|rss2?|rdf|atom)(/+|$)#', '/', $paged_redirect['path']); // strip off feed endings |
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140 $paged_redirect['path'] = preg_replace('#/comment-page-[0-9]+?(/+)?$#', '/', $paged_redirect['path']); // strip off any existing comment paging |
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141 } |
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142 |
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143 $addl_path = ''; |
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144 if ( is_feed() ) { |
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145 $addl_path = !empty( $addl_path ) ? trailingslashit($addl_path) : ''; |
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146 if ( get_query_var( 'withcomments' ) ) |
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147 $addl_path .= 'comments/'; |
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148 $addl_path .= user_trailingslashit( 'feed/' . ( ( 'rss2' == get_query_var('feed') || 'feed' == get_query_var('feed') ) ? '' : get_query_var('feed') ), 'feed' ); |
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149 $redirect['query'] = remove_query_arg( 'feed', $redirect['query'] ); |
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150 } |
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151 |
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152 if ( get_query_var('paged') > 0 ) { |
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153 $paged = get_query_var('paged'); |
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154 $redirect['query'] = remove_query_arg( 'paged', $redirect['query'] ); |
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155 if ( !is_feed() ) { |
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156 if ( $paged > 1 && !is_single() ) { |
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157 $addl_path = ( !empty( $addl_path ) ? trailingslashit($addl_path) : '' ) . user_trailingslashit("page/$paged", 'paged'); |
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158 } elseif ( !is_single() ) { |
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159 $addl_path = ( !empty( $addl_path ) ? trailingslashit($addl_path) : '' ) . user_trailingslashit($paged_redirect['path'], 'paged'); |
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160 } |
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161 } elseif ( $paged > 1 ) { |
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162 $redirect['query'] = add_query_arg( 'paged', $paged, $redirect['query'] ); |
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163 } |
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164 } |
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165 |
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166 if ( get_option('page_comments') && ( ( 'newest' == get_option('default_comments_page') && get_query_var('cpage') > 0 ) || ( 'newest' != get_option('default_comments_page') && get_query_var('cpage') > 1 ) ) ) { |
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167 $addl_path = ( !empty( $addl_path ) ? trailingslashit($addl_path) : '' ) . user_trailingslashit( 'comment-page-' . get_query_var('cpage'), 'commentpaged' ); |
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168 $redirect['query'] = remove_query_arg( 'cpage', $redirect['query'] ); |
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169 } |
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170 |
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171 $paged_redirect['path'] = user_trailingslashit( preg_replace('|/index.php/?$|', '/', $paged_redirect['path']) ); // strip off trailing /index.php/ |
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172 if ( !empty( $addl_path ) && $wp_rewrite->using_index_permalinks() && strpos($paged_redirect['path'], '/index.php/') === false ) |
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173 $paged_redirect['path'] = trailingslashit($paged_redirect['path']) . 'index.php/'; |
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174 if ( !empty( $addl_path ) ) |
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175 $paged_redirect['path'] = trailingslashit($paged_redirect['path']) . $addl_path; |
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176 $redirect_url = $paged_redirect['scheme'] . '://' . $paged_redirect['host'] . $paged_redirect['path']; |
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177 $redirect['path'] = $paged_redirect['path']; |
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178 } |
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179 } |
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180 |
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181 // tack on any additional query vars |
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182 $redirect['query'] = preg_replace( '#^\??&*?#', '', $redirect['query'] ); |
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183 if ( $redirect_url && !empty($redirect['query']) ) { |
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184 if ( strpos($redirect_url, '?') !== false ) |
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185 $redirect_url .= '&'; |
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186 else |
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187 $redirect_url .= '?'; |
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188 $redirect_url .= $redirect['query']; |
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189 } |
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190 |
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191 if ( $redirect_url ) |
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192 $redirect = @parse_url($redirect_url); |
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193 |
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194 // www.example.com vs example.com |
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195 $user_home = @parse_url(get_option('home')); |
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196 if ( !empty($user_home['host']) ) |
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197 $redirect['host'] = $user_home['host']; |
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198 if ( empty($user_home['path']) ) |
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199 $user_home['path'] = '/'; |
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200 |
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201 // Handle ports |
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202 if ( !empty($user_home['port']) ) |
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203 $redirect['port'] = $user_home['port']; |
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204 else |
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205 unset($redirect['port']); |
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206 |
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207 // trailing /index.php |
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208 $redirect['path'] = preg_replace('|/index.php/*?$|', '/', $redirect['path']); |
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209 |
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210 // Remove trailing spaces from the path |
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211 $redirect['path'] = preg_replace( '#(%20| )+$#', '', $redirect['path'] ); |
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212 |
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213 if ( !empty( $redirect['query'] ) ) { |
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214 // Remove trailing spaces from certain terminating query string args |
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215 $redirect['query'] = preg_replace( '#((p|page_id|cat|tag)=[^&]*?)(%20| )+$#', '$1', $redirect['query'] ); |
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216 |
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217 // Clean up empty query strings |
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218 $redirect['query'] = trim(preg_replace( '#(^|&)(p|page_id|cat|tag)=?(&|$)#', '&', $redirect['query']), '&'); |
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219 |
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220 // Remove redundant leading ampersands |
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221 $redirect['query'] = preg_replace( '#^\??&*?#', '', $redirect['query'] ); |
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222 } |
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223 |
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224 // strip /index.php/ when we're not using PATHINFO permalinks |
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225 if ( !$wp_rewrite->using_index_permalinks() ) |
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226 $redirect['path'] = str_replace('/index.php/', '/', $redirect['path']); |
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227 |
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228 // trailing slashes |
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229 if ( is_object($wp_rewrite) && $wp_rewrite->using_permalinks() && !is_404() && (!is_front_page() || ( is_front_page() && (get_query_var('paged') > 1) ) ) ) { |
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230 $user_ts_type = ''; |
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231 if ( get_query_var('paged') > 0 ) { |
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232 $user_ts_type = 'paged'; |
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233 } else { |
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234 foreach ( array('single', 'category', 'page', 'day', 'month', 'year', 'home') as $type ) { |
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235 $func = 'is_' . $type; |
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236 if ( call_user_func($func) ) { |
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237 $user_ts_type = $type; |
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238 break; |
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239 } |
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240 } |
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241 } |
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242 $redirect['path'] = user_trailingslashit($redirect['path'], $user_ts_type); |
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243 } elseif ( is_front_page() ) { |
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244 $redirect['path'] = trailingslashit($redirect['path']); |
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245 } |
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246 |
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247 // Always trailing slash the Front Page URL |
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248 if ( trailingslashit( $redirect['path'] ) == trailingslashit( $user_home['path'] ) ) |
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249 $redirect['path'] = trailingslashit($redirect['path']); |
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250 |
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251 // Ignore differences in host capitalization, as this can lead to infinite redirects |
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252 // Only redirect no-www <=> yes-www |
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253 if ( strtolower($original['host']) == strtolower($redirect['host']) || |
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254 ( strtolower($original['host']) != 'www.' . strtolower($redirect['host']) && 'www.' . strtolower($original['host']) != strtolower($redirect['host']) ) ) |
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255 $redirect['host'] = $original['host']; |
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256 |
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257 $compare_original = array($original['host'], $original['path']); |
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258 |
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259 if ( !empty( $original['port'] ) ) |
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260 $compare_original[] = $original['port']; |
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261 |
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262 if ( !empty( $original['query'] ) ) |
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263 $compare_original[] = $original['query']; |
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264 |
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265 $compare_redirect = array($redirect['host'], $redirect['path']); |
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266 |
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267 if ( !empty( $redirect['port'] ) ) |
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268 $compare_redirect[] = $redirect['port']; |
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269 |
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270 if ( !empty( $redirect['query'] ) ) |
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271 $compare_redirect[] = $redirect['query']; |
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272 |
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273 if ( $compare_original !== $compare_redirect ) { |
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274 $redirect_url = $redirect['scheme'] . '://' . $redirect['host']; |
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275 if ( !empty($redirect['port']) ) |
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276 $redirect_url .= ':' . $redirect['port']; |
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277 $redirect_url .= $redirect['path']; |
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278 if ( !empty($redirect['query']) ) |
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279 $redirect_url .= '?' . $redirect['query']; |
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280 } |
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281 |
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282 if ( $redirect_url == $requested_url ) |
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283 return false; |
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284 |
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285 // Note that you can use the "redirect_canonical" filter to cancel a canonical redirect for whatever reason by returning FALSE |
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286 $redirect_url = apply_filters('redirect_canonical', $redirect_url, $requested_url); |
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287 |
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288 if ( !$redirect_url || $redirect_url == $requested_url ) // yes, again -- in case the filter aborted the request |
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289 return false; |
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290 |
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291 if ( $do_redirect ) { |
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292 // protect against chained redirects |
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293 if ( !redirect_canonical($redirect_url, false) ) { |
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294 wp_redirect($redirect_url, 301); |
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295 exit(); |
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296 } else { |
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297 // Debug |
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298 // die("1: $redirect_url<br />2: " . redirect_canonical( $redirect_url, false ) ); |
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299 return false; |
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300 } |
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301 } else { |
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302 return $redirect_url; |
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303 } |
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304 } |
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305 |
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306 /** |
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307 * Attempts to guess correct post based on query vars. |
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308 * |
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309 * @since 2.3.0 |
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310 * @uses $wpdb |
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311 * |
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312 * @return bool|string Returns False, if it can't find post, returns correct |
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313 * location on success. |
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314 */ |
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315 function redirect_guess_404_permalink() { |
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316 global $wpdb; |
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317 |
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318 if ( !get_query_var('name') ) |
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319 return false; |
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320 |
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321 $where = $wpdb->prepare("post_name LIKE %s", get_query_var('name') . '%'); |
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322 |
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323 // if any of year, monthnum, or day are set, use them to refine the query |
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324 if ( get_query_var('year') ) |
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325 $where .= $wpdb->prepare(" AND YEAR(post_date) = %d", get_query_var('year')); |
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326 if ( get_query_var('monthnum') ) |
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327 $where .= $wpdb->prepare(" AND MONTH(post_date) = %d", get_query_var('monthnum')); |
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328 if ( get_query_var('day') ) |
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329 $where .= $wpdb->prepare(" AND DAYOFMONTH(post_date) = %d", get_query_var('day')); |
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330 |
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331 $post_id = $wpdb->get_var("SELECT ID FROM $wpdb->posts WHERE $where AND post_status = 'publish'"); |
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332 if ( !$post_id ) |
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333 return false; |
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334 return get_permalink($post_id); |
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335 } |
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336 |
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337 add_action('template_redirect', 'redirect_canonical'); |
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338 |
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339 ?> |