Merge remote-tracking branch 'upstream/master' into bug_13514

src/data.js

@@ -85,7 +85,7 @@ Data.prototype = {
 		// Either a valid cache is found, or will be created.
 		// New caches will be created and the unlock returned,
 		// allowing direct access to the newly created
-		// empty data object.
+		// empty data object. A valid owner object must be provided.
 		var cache = this.cache[ this.key( owner ) ];
 
 		return key === undefined ?
@@ -255,9 +255,12 @@ jQuery.fn.extend({
 			var data,
 					camelKey = jQuery.camelCase( key );
 
-			// Get the Data...
-			if ( value === undefined ) {
-
+			// The calling jQuery object (element matches) is not empty
+			// (and therefore has an element appears at this[0]) and the
+			// `value` parameter was not undefined. An empty jQuery object
+			// will result in `undefined` for elem = this[0] which will
+			// throw an exception if an attempt to read a data cache is made.
+			if ( elem && value === undefined ) {
 				// Attempt to get data from the cache
 				// with the key as-is
 				data = data_user.get( elem, key );

test/unit/data.js

@@ -469,7 +469,7 @@ if (window.JSON && window.JSON.stringify) {
 	});
 }
 
-test("jQuery.data should follow html5 specification regarding camel casing", function() {
+test(".data should follow html5 specification regarding camel casing", function() {
 	expect(12);
 
 	var div = jQuery("<div id='myObject' data-w-t-f='ftw' data-big-a-little-a='bouncing-b' data-foo='a' data-foo-bar='b' data-foo-bar-baz='c'></div>")
@@ -535,7 +535,7 @@ test(".data should not miss attr() set data-* with hyphenated property names", f
 	deepEqual( b.data("long-param"), { a: 2 }, "data with property long-param was found, 2" );
 });
 
-test("jQuery.data supports interoperable hyphenated/camelCase get/set of properties with arbitrary non-null|NaN|undefined values", function() {
+test(".data supports interoperable hyphenated/camelCase get/set of properties with arbitrary non-null|NaN|undefined values", function() {
 
 	var div = jQuery("<div/>", { id: "hyphened" }).appendTo("#qunit-fixture"),
 		datas = {
@@ -566,7 +566,7 @@ test("jQuery.data supports interoperable hyphenated/camelCase get/set of propert
 	});
 });
 
-test("jQuery.data supports interoperable removal of hyphenated/camelCase properties", function() {
+test(".data supports interoperable removal of hyphenated/camelCase properties", function() {
 	var div = jQuery("<div/>", { id: "hyphened" }).appendTo("#qunit-fixture"),
 		datas = {
 			"non-empty": "a string",
@@ -598,7 +598,7 @@ test("jQuery.data supports interoperable removal of hyphenated/camelCase propert
 	});
 });
 
-test( "jQuery.fn.removeData supports removal of hyphenated properties via array (#12786)", function( assert ) {
+test( ".removeData supports removal of hyphenated properties via array (#12786)", function( assert ) {
 	expect( 4 );
 
 	var div, plain, compare;
@@ -631,7 +631,7 @@ test( "jQuery.fn.removeData supports removal of hyphenated properties via array
 });
 
 // Test originally by Moschel
-test("Triggering the removeData should not throw exceptions. (#10080)", function() {
+test(".removeData should not throw exceptions. (#10080)", function() {
 	expect(1);
 	stop();
 	var frame = jQuery("#loadediframe");
@@ -643,7 +643,7 @@ test("Triggering the removeData should not throw exceptions. (#10080)", function
 	frame.attr("src", "data/iframe.html?param=true");
 });
 
-test( "Only check element attributes once when calling .data() - #8909", function() {
+test( ".data only checks element attributes once. #8909", function() {
 	expect( 2 );
 	var testing = {
 			"test": "testing",
@@ -663,10 +663,21 @@ test( "Only check element attributes once when calling .data() - #8909", functio
 	element.remove();
 });
 
-test( "JSON data- attributes can have newlines", function() {
+test( "data-* with JSON value can have newlines", function() {
 	expect(1);
 
 	var x = jQuery("<div data-some='{\n\"foo\":\n\t\"bar\"\n}'></div>");
 	equal( x.data("some").foo, "bar", "got a JSON data- attribute with spaces" );
 	x.remove();
 });
+
+test(".data doesn't throw when calling selection is empty. #13551", function() {
+	expect(1);
+
+	try {
+		jQuery( null ).data( "prop" );
+		ok( true, "jQuery(null).data('prop') does not throw" );
+	} catch ( e ) {
+		ok( false, e.message );
+	}
+});