Merged with WordPress 2.5, unstable, only for testing

git-svn-id: http://svn.automattic.com/wordpress-mu/trunk@1218 7be80a69-a1ef-0310-a953-fb0f7c49ff36

1 files changed, 64 insertions, 22 deletions

diff --git a/wp-includes/canonical.php b/wp-includes/canonical.php
index 9226f3e..5ad4457 100644
--- a/wp-includes/canonical.php
+++ b/wp-includes/canonical.php
@@ -1,8 +1,39 @@
 <?php
-// Based on "Permalink Redirect" from Scott Yang and "Enforce www. Preference" by Mark Jaquith
-
-function redirect_canonical($requested_url=NULL, $do_redirect=true) {
-	global $wp_rewrite, $posts, $is_IIS;
+/**
+ * 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
+ */
+
+/**
+ * redirect_canonical() - 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
+ * @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;
 
 	if ( is_feed() || is_trackback() || is_search() || is_comments_popup() || is_admin() || $is_IIS || ( isset($_POST) && count($_POST) ) || is_preview() )
 		return;
@@ -156,39 +187,50 @@ function redirect_canonical($requested_url=NULL, $do_redirect=true) {
 			$redirect_url .= '?' . $redirect['query'];
 	}
 
-	if ( $redirect_url && $redirect_url != $requested_url ) {
-		// var_dump($redirect_url); die();
-		$redirect_url = apply_filters('redirect_canonical', $redirect_url, $requested_url);
-		if ( $do_redirect) {
-			// protect against chained redirects
-			if ( !redirect_canonical($redirect_url, false) ) {
-				wp_redirect($redirect_url, 301);
-				exit();
-			} else {
-				return false;
-			}
+	if ( !$redirect_url || $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 {
-			return $redirect_url;
+			return false;
 		}
 	} else {
-		return false;
+		return $redirect_url;
 	}
 }
 
+/**
+ * redirect_guess_404_permalink() - Tries to guess correct post based on query vars
+ *
+ * @since 2.3
+ * @uses $wpdb
+ *
+ * @return bool|string Returns False, if it can't find post, returns correct location on success.
+ */
 function redirect_guess_404_permalink() {
-	global $wp_query, $wpdb;
+	global $wpdb;
 	if ( !get_query_var('name') )
 		return false;
 
-	$where = "post_name LIKE '" . $wpdb->escape(get_query_var('name')) . "%'";
+	$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 .= " AND YEAR(post_date) = '" . $wpdb->escape(get_query_var('year')) . "'";
+		$where .= $wpdb->prepare(" AND YEAR(post_date) = %d", get_query_var('year'));
 	if ( get_query_var('monthnum') )
-		$where .= " AND MONTH(post_date) = '" . $wpdb->escape(get_query_var('monthnum')) . "'";
+		$where .= $wpdb->prepare(" AND MONTH(post_date) = %d", get_query_var('monthnum'));
 	if ( get_query_var('day') )
-		$where .= " AND DAYOFMONTH(post_date) = '" . $wpdb->escape(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 )