Ticket #1562: extend-1562.diff

core.js

@@ -579 +579 @@
                                         continue;
 
                                 // Recurse if we're merging object values
-                                if ( deep && copy && typeof copy == "object" && src && !copy.nodeType )
-                                        target[ name ] = jQuery.extend( deep, src, copy );
+                                if ( deep && copy && typeof copy == "object" && !copy.nodeType )
+                                        target[ name ] = jQuery.extend( deep, 
+                                                // Never move original objects, clone them
+                                                src || copy.length !== undefined ? [ ] : { }
+                                        , copy );
 
                                 // Don't bring in undefined values
                                 else if ( copy !== undefined )