Ticket #9466: 9466.diff

wp-includes/link-template.php

@@ -88 +88 @@
                 $leavename? '' : '%postname%',
                 '%post_id%',
                 '%category%',
+                '%tag%',
                 '%author%',
                 $leavename? '' : '%pagename%',
         );
@@ -129 +130 @@
                         }
                 }
 
+                $tag = '';
+                if ( strpos($permalink, '%tag%') !== false ) {
+                        $tags = get_the_tags($post->ID);
+                        if ( !empty( $tags ) ) {
+                                usort($tags, '_usort_terms_by_ID'); // order by ID
+                                $tag = $tags[0]->slug;
+                        }
+                }
+
                 $author = '';
                 if ( strpos($permalink, '%author%') !== false ) {
                         $authordata = get_userdata($post->post_author);
@@ -147 +157 @@
                         $post->post_name,
                         $post->ID,
                         $category,
+                        $tag,
                         $author,
                         $post->post_name,
                 );