Landing pull request 461. Adds a due diligence check for pre-defined data-*...

Landing pull request 461. Adds a due diligence check for pre-defined data-* attrs during removal. Fixes #10026.

More Details:
 - https://github.com/jquery/jquery/pull/461
 - http://bugs.jquery.com/ticket/10026

src/data.js

@@ -167,6 +167,11 @@ jQuery.extend({
 
 				delete thisCache[ name ];
 
+				// Check the actual element for predefined data-* attrs, #10027
+				if ( jQuery.attr( elem, "data-" + name ) ) {
+					jQuery.removeAttr( elem, "data-" + name );
+				}
+
 				// If there is no data left in the cache, we want to continue
 				// and let the cache object itself get destroyed
 				if ( !isEmptyDataObject(thisCache) ) {

test/unit/data.js

@@ -568,7 +568,7 @@ test("jQuery.data supports interoperable removal of hyphenated/camelCase propert
 			"some-json": '{ "foo": "bar" }'
 		};
 
-	expect( 27 );
+	expect( 29 );
 
 	jQuery.each( datas, function( key, val ) {
 		div.data( key, val );
@@ -581,4 +581,15 @@ test("jQuery.data supports interoperable removal of hyphenated/camelCase propert
 		equal( div.data( key ), undefined, "get: " + key );
 
 	});
+
+	div.remove();
+
+	// Covers #10027
+	div = jQuery("<div data-msg='hello'></div>");
+
+	equal( div.data("msg"), "hello", "<div data-msg='hello'></div> has expected data" );
+
+	div.removeData("msg");
+
+	equal( div.data("msg"), undefined, "data-msg removed correctly" );
 });