Ticket #4109: 4109.diff

wp-includes/post.php

@@ -784 +784 @@
         return wp_update_post(array('post_status' => 'publish', 'ID' => $post_id, 'no_filter' => true));
 }
 
-function wp_set_post_tags( $post_id = 0, $tags = '' ) {
+function wp_add_post_tags($post_id = 0, $tags = '') {
+        return wp_set_post_tags($post_id, $tags, true);
+}
+
+function wp_set_post_tags( $post_id = 0, $tags = '', $append = false ) {
+        /* $append - true = don't delete existing tags, just add on, false = replace the tags with the new tags */
         global $wpdb;
         
         $post_id = (int) $post_id;
         
         if ( !$post_id )
                 return false;
-
-        $tags = explode( ',', $tags );
+        
+        // prevent warnings for unintialized variables
+        $tag_ids = array();
+        
+        $tags = (is_array($tags)) ? $tags : explode( ',', $tags );
+        
         foreach ( $tags as $tag ) {
                 $tag = trim( $tag );
                 if ( !$tag_slug = sanitize_title( $tag ) )
@@ -801 +810 @@
                         $tag_id = wp_create_tag( $tag );
                 $tag_ids[] = $tag_id;
         }
-
-        if ( !is_array( $tag_ids ) )
+        
+        if ( empty($tag_ids) )
                 return false;
-
+        
         $tag_ids = array_unique( $tag_ids );
-
+        
         // First the old tags
         $old_tags = $wpdb->get_col("
                 SELECT category_id
                 FROM $wpdb->post2cat
                 WHERE post_id = '$post_id' AND rel_type = 'tag'");
-
+        
         if ( !$old_tags ) {
                 $old_tags = array();
         } else {
                 $old_tags = array_unique( $old_tags );
         }
-
+        
         // Delete any?
         $delete_tags = array_diff( $old_tags, $tag_ids);
-        if ( $delete_tags ) {
+        if ( $delete_tags && !$append ) {
                 foreach ( $delete_tags as $del ) {
                         $wpdb->query("
                                 DELETE FROM $wpdb->post2cat
@@ -831 +840 @@
                                 ");
                 }
         }
-
+        
         // Add any?
         $add_tags = array_diff( $tag_ids, $old_tags );
         if ( $add_tags ) {
@@ -843 +852 @@
                                         VALUES ('$post_id', '$new_tag', 'tag')");
                 }
         }
-
+        
         // Update category counts.
         $all_affected_tags = array_unique( array_merge( $tag_ids, $old_tags ) );
         foreach ( $all_affected_tags as $tag_id ) {