Fixes #13550. .data should not miss attr() set data-* with hyphenated property...

Fixes #13550. .data should not miss attr() set data-* with hyphenated property names. Closes gh-1189

src/data.js

@@ -30,7 +30,7 @@ Data.prototype = {
 		if ( !unlock ) {
 			unlock = Data.uid++;
 			descriptor[ this.expando ] = { value: unlock };
-			
+
 			// Secure it in a non-enumerable, non-writable property
 			try {
 				Object.defineProperties( owner, descriptor );
@@ -312,7 +312,8 @@ jQuery.fn.extend({
 });
 
 function dataAttr( elem, key, data ) {
-	var name;
+	var name,
+			camelKey = jQuery.camelCase( key );
 
 	// If nothing was found internally, try to fetch any
 	// data from the HTML5 data-* attribute
@@ -333,7 +334,7 @@ function dataAttr( elem, key, data ) {
 			} catch( e ) {}
 
 			// Make sure we set the data so it isn't changed later
-			data_user.set( elem, key, data );
+			data_user.set( elem, camelKey, data );
 		} else {
 			data = undefined;
 		}

test/unit/data.js

@@ -515,14 +515,22 @@ test(".data should not miss preset data-* w/ hyphenated property names", functio
 });
 
 test(".data should not miss attr() set data-* with hyphenated property names", function() {
-	expect(1);
+	expect(2);
+
+	var div1 = jQuery("<div/>").appendTo("#qunit-fixture");
+
+	div1.attr( "data-long-param", "test" );
+	div1.data( "long-param", { a: 2 });
+
+	deepEqual( div1.data("long-param"), { a: 2 }, "data with property long-param was found" );
 
-	var div = jQuery("<div/>").appendTo("#qunit-fixture");
+	var div2 = jQuery("<div/>").appendTo("#qunit-fixture");
 
-	div.attr( "data-long-param", "test" );
-	div.data( "long-param", { a: 2 });
+	div2.attr( "data-long-param", "test" );
+	div2.data( "long-param" );
+	div2.data( "long-param", { a: 2 });
 
-	deepEqual( div.data("long-param"), { a: 2 }, "data with property long-param was found" );
+	deepEqual( div2.data("long-param"), { a: 2 }, "data with property long-param was found" );
 });
 
 test("jQuery.data supports interoperable hyphenated/camelCase get/set of properties with arbitrary non-null|NaN|undefined values", function() {