From b6e3b188e739959eb5348588ffab3c96681b2aed Mon Sep 17 00:00:00 2001
From: dd32 <dd32@1a063a9b-81f0-0310-95a4-ce76da25c4cd>
Date: Sat, 20 Mar 2010 06:27:27 +0000
Subject: [PATCH] Only allow %category% to be a valid category attached to the
 current post when using %category% in a permalink structure. Fixes #11807

git-svn-id: http://svn.automattic.com/wordpress/trunk@13781 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/canonical.php | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/wp-includes/canonical.php b/wp-includes/canonical.php
index 10b3b4ddfe..428e92ffcb 100644
--- a/wp-includes/canonical.php
+++ b/wp-includes/canonical.php
@@ -164,6 +164,11 @@ function redirect_canonical($requested_url=null, $do_redirect=true) {
 				}
 
 			}
+		} elseif ( is_single() && strpos($wp_rewrite->permalink_structure, '%category%') !== false ) {
+			$category = get_term_by('slug', get_query_var('category_name'), 'category');
+			$post_terms = wp_get_object_terms($wp_query->get_queried_object_id(), 'category');
+			if ( ! in_array($category, $post_terms) )
+				$redirect_url = get_permalink($wp_query->get_queried_object_id());
 		}
 
 		// paging and feeds