switch to term_id and name for category sorting. see #4189. sort by term_id for category permalinks, by name for get_the_category(). fixes #4335 for trunk. Props Erik Barzeski for the find.

git-svn-id: http://svn.automattic.com/wordpress/trunk@5590 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/category-template.php

@@ -69,15 +69,24 @@ function get_the_category($id = false) {
 	$categories = get_object_terms($id, 'category');
 
 	if ( !empty($categories) )
-		usort($categories, '_get_the_category_usort');
+		usort($categories, '_usort_terms_by_name');
 	else
 		$categories = array();
 
 	return $categories;
 }
 
-function _get_the_category_usort($a, $b) {
+function _usort_terms_by_name($a, $b) {
-	return strcmp($a->category_name, $b->category_name);
+	return strcmp($a->name, $b->name);
+}
+
+function _usort_terms_by_ID($a, $b) { 
+	if ( $a->term_id > $b->term_id ) 
+		return 1; 
+	elseif ( $a->term_id < $b->term_id ) 
+		return -1; 
+	else 
+		return 0; 
 }
 
 function get_the_category_by_ID($cat_ID) {

wp-includes/link-template.php

@@ -73,6 +73,8 @@ function get_permalink($id = 0) {
 		$category = '';
 		if (strpos($permalink, '%category%') !== false) {
 			$cats = get_the_category($post->ID);
+			if ( $cats )
+				usort($cats, '_usort_terms_by_ID'); // order by ID
 			$category = $cats[0]->slug;
 			if ( $parent=$cats[0]->parent )
 				$category = get_category_parents($parent, FALSE, '/', TRUE) . $category;