CaffGeek/MBACNationals

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Web.Admin/2014/wordpress/wp-includes/canonical.php

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5 days
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<?php
/**
 * Canonical API to handle WordPress Redirecting
 *
 * Based on "Permalink Redirect" from Scott Yang and "Enforce www. Preference"
 * by Mark Jaquith
 *
 * @author Scott Yang
 * @author Mark Jaquith
 * @package WordPress
 * @since 2.3.0
 */

/**
 * Redirects incoming links to the proper URL based on the site url.
 *
 * Search engines consider www.somedomain.com and somedomain.com to be two
 * different URLs when they both go to the same location. This SEO enhancement
 * prevents penality for duplicate content by redirecting all incoming links to
 * one or the other.
 *
 * Prevents redirection for feeds, trackbacks, searches, comment popup, and
 * admin URLs. Does not redirect on IIS, page/post previews, and on form data.
 *
 * Will also attempt to find the correct link when a user enters a URL that does
 * not exist based on exact WordPress query. Will instead try to parse the URL
 * or query in an attempt to figure the correct page to go to.
 *
 * @since 2.3.0
 * @uses $wp_rewrite
 * @uses $is_IIS
 *
 * @param string $requested_url Optional. The URL that was requested, used to
 *        figure if redirect is needed.
 * @param bool $do_redirect Optional. Redirect to the new URL.
 * @return null|false|string Null, if redirect not needed. False, if redirect
 *        not needed or the string of the URL
 */
function redirect_canonical($requested_url=null, $do_redirect=true) {
    global $wp_rewrite, $is_IIS, $wp_query, $wpdb;

    if ( is_trackback() || is_search() || is_comments_popup() || is_admin() || $is_IIS || ( isset($_POST) && count($_POST) ) || is_preview() || is_robots() )
        return;

    if ( !$requested_url ) {
        // build the URL in the address bar
        $requested_url  = ( !empty($_SERVER['HTTPS'] ) && strtolower($_SERVER['HTTPS']) == 'on' ) ? 'https://' : 'http://';
        $requested_url .= $_SERVER['HTTP_HOST'];
        $requested_url .= $_SERVER['REQUEST_URI'];
    }

    $original = @parse_url($requested_url);
    if ( false === $original )
        return;

    // Some PHP setups turn requests for / into /index.php in REQUEST_URI
    // See: http://trac.wordpress.org/ticket/5017
    // See: http://trac.wordpress.org/ticket/7173
    // Disabled, for now:
    // $original['path'] = preg_replace('|/index\.php$|', '/', $original['path']);

    $redirect = $original;
    $redirect_url = false;

    // Notice fixing
    if ( !isset($redirect['path']) )  $redirect['path'] = '';
    if ( !isset($redirect['query']) ) $redirect['query'] = '';

    if ( is_singular() && 1 > $wp_query->post_count && ($id = get_query_var('p')) ) {

        $vars = $wpdb->get_results( $wpdb->prepare("SELECT post_type, post_parent FROM $wpdb->posts WHERE ID = %d", $id) );

        if ( isset($vars[0]) && $vars = $vars[0] ) {
            if ( 'revision' == $vars->post_type && $vars->post_parent > 0 )
                $id = $vars->post_parent;

            if ( $redirect_url = get_permalink($id) )
                $redirect['query'] = remove_query_arg(array('p', 'page_id', 'attachment_id'), $redirect['query']);
        }
    }

    // These tests give us a WP-generated permalink
    if ( is_404() ) {
        $redirect_url = redirect_guess_404_permalink();
    } elseif ( is_object($wp_rewrite) && $wp_rewrite->using_permalinks() ) {
        // rewriting of old ?p=X, ?m=2004, ?m=200401, ?m=20040101
        if ( is_attachment() && !empty($_GET['attachment_id']) && ! $redirect_url ) {
            if ( $redirect_url = get_attachment_link(get_query_var('attachment_id')) )
                $redirect['query'] = remove_query_arg('attachment_id', $redirect['query']);
        } elseif ( is_single() && !empty($_GET['p']) && ! $redirect_url ) {
            if ( $redirect_url = get_permalink(get_query_var('p')) )
                $redirect['query'] = remove_query_arg('p', $redirect['query']);
            if ( get_query_var( 'page' ) ) {
                $redirect_url = trailingslashit( $redirect_url ) . user_trailingslashit( get_query_var( 'page' ), 'single_paged' );
                $redirect['query'] = remove_query_arg( 'page', $redirect['query'] );
            }
        } elseif ( is_single() && !empty($_GET['name'])  && ! $redirect_url ) {
            if ( $redirect_url = get_permalink( $wp_query->get_queried_object_id() ) )
                $redirect['query'] = remove_query_arg('name', $redirect['query']);
        } elseif ( is_page() && !empty($_GET['page_id']) && ! $redirect_url ) {
            if ( $redirect_url = get_permalink(get_query_var('page_id')) )
                $redirect['query'] = remove_query_arg('page_id', $redirect['query']);
        } elseif ( !empty($_GET['m']) && ( is_year() || is_month() || is_day() ) ) {
            $m = get_query_var('m');
            switch ( strlen($m) ) {
                case 4: // Yearly
                    $redirect_url = get_year_link($m);
                    break;
                case 6: // Monthly
                    $redirect_url = get_month_link( substr($m, 0, 4), substr($m, 4, 2) );
                    break;
                case 8: // Daily
                    $redirect_url = get_day_link(substr($m, 0, 4), substr($m, 4, 2), substr($m, 6, 2));
                    break;
            }
            if ( $redirect_url )
                $redirect['query'] = remove_query_arg('m', $redirect['query']);
        // now moving on to non ?m=X year/month/day links
        } elseif ( is_day() && get_query_var('year') && get_query_var('monthnum') && !empty($_GET['day']) ) {
            if ( $redirect_url = get_day_link(get_query_var('year'), get_query_var('monthnum'), get_query_var('day')) )
                $redirect['query'] = remove_query_arg(array('year', 'monthnum', 'day'), $redirect['query']);
        } elseif ( is_month() && get_query_var('year') && !empty($_GET['monthnum']) ) {
            if ( $redirect_url = get_month_link(get_query_var('year'), get_query_var('monthnum')) )
                $redirect['query'] = remove_query_arg(array('year', 'monthnum'), $redirect['query']);
        } elseif ( is_year() && !empty($_GET['year']) ) {
            if ( $redirect_url = get_year_link(get_query_var('year')) )
                $redirect['query'] = remove_query_arg('year', $redirect['query']);
        } elseif ( is_category() && !empty($_GET['cat']) && preg_match( '|^[0-9]+$|', $_GET['cat'] ) ) {
            if ( $redirect_url = get_category_link(get_query_var('cat')) )
                $redirect['query'] = remove_query_arg('cat', $redirect['query']);
        } elseif ( is_author() && !empty($_GET['author']) && preg_match( '|^[0-9]+$|', $_GET['author'] ) ) {
            $author = get_userdata(get_query_var('author'));
            if ( false !== $author && $redirect_url = get_author_posts_url($author->ID, $author->user_nicename) )
                $redirect['query'] = remove_query_arg('author', $redirect['author']);
        }

    // paging and feeds
        if ( get_query_var('paged') || is_feed() || get_query_var('cpage') ) {
            if ( !$redirect_url )
                $redirect_url = $requested_url;
            $paged_redirect = @parse_url($redirect_url);
            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'] ) ) {
                // Strip off paging and feed
                $paged_redirect['path'] = preg_replace('#/page/[0-9]+?(/+)?$#', '/', $paged_redirect['path']); // strip off any existing paging
                $paged_redirect['path'] = preg_replace('#/(comments/?)?(feed|rss2?|rdf|atom)(/+|$)#', '/', $paged_redirect['path']); // strip off feed endings
                $paged_redirect['path'] = preg_replace('#/comment-page-[0-9]+?(/+)?$#', '/', $paged_redirect['path']); // strip off any existing comment paging
            }

            $addl_path = '';
            if ( is_feed() ) {
                $addl_path = !empty( $addl_path ) ? trailingslashit($addl_path) : '';
                if ( get_query_var( 'withcomments' ) )
                    $addl_path .= 'comments/';
                $addl_path .= user_trailingslashit( 'feed/' . ( ( 'rss2' ==  get_query_var('feed') || 'feed' == get_query_var('feed') ) ? '' : get_query_var('feed') ), 'feed' );
                $redirect['query'] = remove_query_arg( 'feed', $redirect['query'] );
            }

            if ( get_query_var('paged') > 0 ) {
                $paged = get_query_var('paged');
                $redirect['query'] = remove_query_arg( 'paged', $redirect['query'] );
                if ( !is_feed() ) {
                    if ( $paged > 1 && !is_single() ) {
                        $addl_path = ( !empty( $addl_path ) ? trailingslashit($addl_path) : '' ) . user_trailingslashit("page/$paged", 'paged');
                    } elseif ( !is_single() ) {
                        $addl_path = ( !empty( $addl_path ) ? trailingslashit($addl_path) : '' ) . user_trailingslashit($paged_redirect['path'], 'paged');
                    }
                } elseif ( $paged > 1 ) {
                    $redirect['query'] = add_query_arg( 'paged', $paged, $redirect['query'] );
                }
            }

            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 ) ) ) {
                $addl_path = ( !empty( $addl_path ) ? trailingslashit($addl_path) : '' ) . user_trailingslashit( 'comment-page-' . get_query_var('cpage'), 'commentpaged' );
                $redirect['query'] = remove_query_arg( 'cpage', $redirect['query'] );
            }

            $paged_redirect['path'] = user_trailingslashit( preg_replace('|/index.php/?$|', '/', $paged_redirect['path']) ); // strip off trailing /index.php/
            if ( !empty( $addl_path ) && $wp_rewrite->using_index_permalinks() && strpos($paged_redirect['path'], '/index.php/') === false )
                $paged_redirect['path'] = trailingslashit($paged_redirect['path']) . 'index.php/';
            if ( !empty( $addl_path ) )
                $paged_redirect['path'] = trailingslashit($paged_redirect['path']) . $addl_path;
            $redirect_url = $paged_redirect['scheme'] . '://' . $paged_redirect['host'] . $paged_redirect['path'];
            $redirect['path'] = $paged_redirect['path'];
        }
    }

    // tack on any additional query vars
    $redirect['query'] = preg_replace( '#^\??&*?#', '', $redirect['query'] );
    if ( $redirect_url && !empty($redirect['query']) ) {
        if ( strpos($redirect_url, '?') !== false )
            $redirect_url .= '&';
        else
            $redirect_url .= '?';
        $redirect_url .= $redirect['query'];
    }

    if ( $redirect_url )
        $redirect = @parse_url($redirect_url);

    // www.example.com vs example.com
    $user_home = @parse_url(get_option('home'));
    if ( !empty($user_home['host']) )
        $redirect['host'] = $user_home['host'];
    if ( empty($user_home['path']) )
        $user_home['path'] = '/';

    // Handle ports
    if ( !empty($user_home['port']) )
        $redirect['port'] = $user_home['port'];
    else
        unset($redirect['port']);

    // trailing /index.php
    $redirect['path'] = preg_replace('|/index.php/*?$|', '/', $redirect['path']);

    // Remove trailing spaces from the path
    $redirect['path'] = preg_replace( '#(%20| )+$#', '', $redirect['path'] );

    if ( !empty( $redirect['query'] ) ) {
        // Remove trailing spaces from certain terminating query string args
        $redirect['query'] = preg_replace( '#((p|page_id|cat|tag)=[^&]*?)(%20| )+$#', '$1', $redirect['query'] );

        // Clean up empty query strings
        $redirect['query'] = trim(preg_replace( '#(^|&)(p|page_id|cat|tag)=?(&|$)#', '&', $redirect['query']), '&');

        // Remove redundant leading ampersands
        $redirect['query'] = preg_replace( '#^\??&*?#', '', $redirect['query'] );
    }

    // strip /index.php/ when we're not using PATHINFO permalinks
    if ( !$wp_rewrite->using_index_permalinks() )
        $redirect['path'] = str_replace('/index.php/', '/', $redirect['path']);

    // trailing slashes
    if ( is_object($wp_rewrite) && $wp_rewrite->using_permalinks() && !is_404() && (!is_front_page() || ( is_front_page() && (get_query_var('paged') > 1) ) ) ) {
        $user_ts_type = '';
        if ( get_query_var('paged') > 0 ) {
            $user_ts_type = 'paged';
        } else {
            foreach ( array('single', 'category', 'page', 'day', 'month', 'year', 'home') as $type ) {
                $func = 'is_' . $type;
                if ( call_user_func($func) ) {
                    $user_ts_type = $type;
                    break;
                }
            }
        }
        $redirect['path'] = user_trailingslashit($redirect['path'], $user_ts_type);
    } elseif ( is_front_page() ) {
        $redirect['path'] = trailingslashit($redirect['path']);
    }

    // Always trailing slash the Front Page URL
    if ( trailingslashit( $redirect['path'] ) == trailingslashit( $user_home['path'] ) )
        $redirect['path'] = trailingslashit($redirect['path']);

    // Ignore differences in host capitalization, as this can lead to infinite redirects
    // Only redirect no-www <=> yes-www
    if ( strtolower($original['host']) == strtolower($redirect['host']) ||
        ( strtolower($original['host']) != 'www.' . strtolower($redirect['host']) && 'www.' . strtolower($original['host']) != strtolower($redirect['host']) ) )
        $redirect['host'] = $original['host'];

    $compare_original = array($original['host'], $original['path']);

    if ( !empty( $original['port'] ) )
        $compare_original[] = $original['port'];

    if ( !empty( $original['query'] ) )
        $compare_original[] = $original['query'];

    $compare_redirect = array($redirect['host'], $redirect['path']);

    if ( !empty( $redirect['port'] ) )
        $compare_redirect[] = $redirect['port'];

    if ( !empty( $redirect['query'] ) )
        $compare_redirect[] = $redirect['query'];

    if ( $compare_original !== $compare_redirect ) {
        $redirect_url = $redirect['scheme'] . '://' . $redirect['host'];
        if ( !empty($redirect['port']) )
            $redirect_url .= ':' . $redirect['port'];
        $redirect_url .= $redirect['path'];
        if ( !empty($redirect['query']) )
            $redirect_url .= '?' . $redirect['query'];
    }

    if ( $redirect_url == $requested_url )
        return false;

    // Note that you can use the "redirect_canonical" filter to cancel a canonical redirect for whatever reason by returning FALSE
    $redirect_url = apply_filters('redirect_canonical', $redirect_url, $requested_url);

    if ( !$redirect_url || $redirect_url == $requested_url ) // yes, again -- in case the filter aborted the request
        return false;

    if ( $do_redirect ) {
        // protect against chained redirects
        if ( !redirect_canonical($redirect_url, false) ) {
            wp_redirect($redirect_url, 301);
            exit();
        } else {
            // Debug
            // die("1: $redirect_url<br />2: " . redirect_canonical( $redirect_url, false ) );
            return false;
        }
    } else {
        return $redirect_url;
    }
}

/**
 * Attempts to guess correct post based on query vars.
 *
 * @since 2.3.0
 * @uses $wpdb
 *
 * @return bool|string Returns False, if it can't find post, returns correct
 *        location on success.
 */
function redirect_guess_404_permalink() {
    global $wpdb;

    if ( !get_query_var('name') )
        return false;

    $where = $wpdb->prepare("post_name LIKE %s", get_query_var('name') . '%');

    // if any of year, monthnum, or day are set, use them to refine the query
    if ( get_query_var('year') )
        $where .= $wpdb->prepare(" AND YEAR(post_date) = %d", get_query_var('year'));
    if ( get_query_var('monthnum') )
        $where .= $wpdb->prepare(" AND MONTH(post_date) = %d", get_query_var('monthnum'));
    if ( get_query_var('day') )
        $where .= $wpdb->prepare(" AND DAYOFMONTH(post_date) = %d", get_query_var('day'));

    $post_id = $wpdb->get_var("SELECT ID FROM $wpdb->posts WHERE $where AND post_status = 'publish'");
    if ( !$post_id )
        return false;
    return get_permalink($post_id);
}

add_action('template_redirect', 'redirect_canonical');

?>