Index: wordpress/wp-includes/taxonomy.php
===================================================================
--- wordpress/wp-includes/taxonomy.php	(revision 6270)
+++ wordpress/wp-includes/taxonomy.php	(working copy)
@@ -1119,6 +1119,8 @@
 	foreach ($terms as $term) {
 		if ( !$id = is_term($term, $taxonomy) )
 			$id = wp_insert_term($term, $taxonomy);
+		if ( is_wp_error($id) )
+			return $id;
 		$term_ids[] = $id['term_id'];
 		$id = $id['term_taxonomy_id'];
 		$tt_ids[] = $id;