Ticket #16391: 16391.diff

post.php

@@ -3796 +3796 @@
 
         $data = apply_filters( 'wp_update_attachment_metadata', $data, $post->ID );
 
-        return update_post_meta( $post->ID, '_wp_attachment_metadata', $data);
+        if ( ! empty($data) )
+                return update_post_meta( $post->ID, '_wp_attachment_metadata', $data );
+
+        return false;
 }
 
 /**