Make .data(Object) extend the existing data object. Fixes #6692.

src/data.js

@@ -52,9 +52,10 @@ jQuery.extend({
 		// want to manipulate it.
 		if ( typeof name === "object" ) {
 			if ( isNode ) {
-				cache[ id ] = jQuery.extend(true, {}, name);
+				cache[ id ] = jQuery.extend(cache[ id ], name);
+
 			} else {
-				store = jQuery.extend(true, {}, name);
+				store = jQuery.extend(cache[ id ], name);
 				cache[ id ] = function() {
 					return store;
 				};
@@ -63,6 +64,7 @@ jQuery.extend({
 		} else if ( !cache[ id ] ) {
 			if ( isNode ) {
 				cache[ id ] = {};
+
 			} else {
 				store = {};
 				cache[ id ] = function() {

test/unit/data.js

@@ -25,7 +25,7 @@ test("expando", function(){
 });
 
 test("jQuery.data", function() {
-	expect(12);
+	expect(13);
 	var div = document.createElement("div");
 
 	ok( jQuery.data(div, "test") === undefined, "Check for no data exists" );
@@ -47,9 +47,11 @@ test("jQuery.data", function() {
 	jQuery.data(div, "test", null);
 	ok( jQuery.data(div, "test") === null, "Check for null data");
 
+	jQuery.data(div, "test3", "orig");
 	jQuery.data(div, { "test": "in", "test2": "in2" });
 	equals( jQuery.data(div, "test"), "in", "Verify setting an object in data." );
 	equals( jQuery.data(div, "test2"), "in2", "Verify setting an object in data." );
+	equals( jQuery.data(div, "test3"), "orig", "Verify original not overwritten." );
 
 	var obj = {};
 	jQuery.data( obj, "prop", true );
@@ -61,7 +63,7 @@ test("jQuery.data", function() {
 });
 
 test(".data()", function() {
-	expect(1);
+	expect(2);
 
 	var div = jQuery("#foo");
 	div.data("test", "success");