Ticket #5911: 5911-7.diff

wp-includes/post.php

@@ -2390 +2390 @@
                         $post_mimes[] = str_replace('/', '_', $mime);
                 }
 
-                $post_mimes[] = 'default';
-
                 $matches = wp_match_mime_types(array_keys($types), $post_mimes);
+                $matches['default'] = array('default');
 
                 foreach ( $matches as $match => $wilds ) {
                         if ( isset($types[$wilds[0]])) {