Fix #11925, Pass eventHandle to special.teardown. Closes jquerygh-831.

* Added unit test to confirm.
  The third assertion fails without the fix in ./src/event.js

src/event.js

@@ -181,7 +181,7 @@ jQuery.event = {
 			// Remove generic event handler if we removed something and no more handlers exist
 			// (avoids potential for endless recursion during removal of special event handlers)
 			if ( eventType.length === 0 && origCount !== eventType.length ) {
-				if ( !special.teardown || special.teardown.call( elem, namespaces ) === false ) {
+				if ( !special.teardown || special.teardown.call( elem, namespaces, elemData.handle ) === false ) {
 					jQuery.removeEvent( elem, type, elemData.handle );
 				}
 

test/unit/event.js

@@ -1382,6 +1382,21 @@ test("Submit event can be stopped (#11049)", function() {
 	form.remove();
 });
 
+test("on(beforeunload) creates/deletes window property instead of adding/removing event listener", function() {
+	expect(3);
+
+	equal( window.onbeforeunload, null, "window property is null/undefined up until now" );
+
+	var handle = function () {};
+	jQuery(window).on( "beforeunload", handle );
+
+	equal( typeof window.onbeforeunload, "function", "window property is set to a function");
+
+	jQuery(window).off( "beforeunload", handle );
+
+	equal( window.onbeforeunload, null, "window property has been unset to null/undefined" );
+})
+
 test("jQuery.Event( type, props )", function() {
 
 	expect(5);