Make sure that unbinding on a plain javascript object works correctly. Fixes #6184.

src/event.js

@@ -525,10 +525,14 @@ jQuery.event = {
 
 var removeEvent = document.removeEventListener ?
 	function( elem, type, handle ) {
-		elem.removeEventListener( type, handle, false );
+		if ( elem.removeEventListener ) {
+			elem.removeEventListener( type, handle, false );
+		}
 	} : 
 	function( elem, type, handle ) {
-		elem.detachEvent( "on" + type, handle );
+		if ( elem.detachEvent ) {
+			elem.detachEvent( "on" + type, handle );
+		}
 	};
 
 jQuery.Event = function( src ) {

test/unit/event.js

@@ -373,6 +373,35 @@ test("bind(), with different this object", function() {
 	ok( !jQuery.data(jQuery("#firstp")[0], "events"), "Event handler unbound when using different this object and data." );
 });
 
+test("bind()/trigger()/unbind() on plain object", function() {
+	expect( 2 );
+
+	var obj = {};
+
+	// Make sure it doesn't complain when no events are found
+	jQuery(obj).trigger("test");
+
+	// Make sure it doesn't complain when no events are found
+	jQuery(obj).unbind("test");
+
+	jQuery(obj).bind("test", function(){
+		ok( true, "Custom event run." );
+	});
+
+	ok( jQuery(obj).data("events"), "Object has events bound." );
+
+	// Should trigger 1
+	jQuery(obj).trigger("test");
+
+	jQuery(obj).unbind("test");
+
+	// Should trigger 0
+	jQuery(obj).trigger("test");
+
+	// Make sure it doesn't complain when no events are found
+	jQuery(obj).unbind("test");
+});
+
 test("unbind(type)", function() {
 	expect( 0 );