Made it so that you can pass in an event object to the trigger data args and it'll override the custom event object (this way you can pass in the event object of a mousemove to a drag event trigger, for example).

src/event/event.js

@@ -134,10 +134,13 @@ jQuery.event = {
 
 		// Handle triggering a single element
 		} else {
-			var val, ret, fn = jQuery.isFunction( element[ type ] || null );
+			var val, ret, fn = jQuery.isFunction( element[ type ] || null ),
+				// Check to see if we need to provide a fake event, or not
+				evt = !data[0] || !data[0].preventDefault;
 			
 			// Pass along a fake event
-			data.unshift( this.fix({ type: type, target: element }) );
+			if ( evt )
+				data.unshift( this.fix({ type: type, target: element }) );
 
 			// Trigger the event
 			if ( jQuery.isFunction( element.$handle ) )
@@ -147,6 +150,10 @@ jQuery.event = {
 			if ( !fn && element["on"+type] && element["on"+type].apply( element, data ) === false )
 				val = false;
 
+			// Extra functions don't get the custom event object
+			if ( evt )
+				data.shift();
+
 			// Handle triggering of extra function
 			if ( extra && extra.apply( element, data ) === false )
 				val = false;

src/event/eventTest.js

@@ -93,8 +93,8 @@ test("unbind(event)", function() {
 	ok( !el[0].$events, "Removed the events expando after all handlers are unbound." );
 });
 
-test("trigger(event, [data]", function() {
+test("trigger(event, [data], [fn])", function() {
-	expect(28);
+	expect(40);
 
 	var handler = function(event, a, b, c) {
 		equals( event.type, "click", "check passed data" );
@@ -104,6 +104,13 @@ test("trigger(event, [data]", function() {
 		return "test";
 	};
 
+	var handler2 = function(a, b, c) {
+		equals( a, 1, "check passed data" );
+		equals( b, "2", "check passed data" );
+		equals( c, "abc", "check passed data" );
+		return "test2";
+	};
+
 	// Simulate a "native" click
 	$("#firstp")[0].click = function(){
 		ok( true, "Native call was triggered" );
@@ -114,8 +121,8 @@ test("trigger(event, [data]", function() {
 	$("#firstp").bind("click", handler).trigger("click", [1, "2", "abc"]);
 
 	// Triggers handlers, native, and extra fn
-	// Triggers 9
+	// Triggers 8
-	$("#firstp").trigger("click", [1, "2", "abc"], handler);
+	$("#firstp").trigger("click", [1, "2", "abc"], handler2);
 
 	// Simulate a "native" click
 	$("#firstp")[0].click = function(){
@@ -123,12 +130,23 @@ test("trigger(event, [data]", function() {
 	};
 
 	// Trigger only the handlers (no native)
-	// Triggers 4
+	// Triggers 5
 	equals( $("#firstp").triggerHandler("click", [1, "2", "abc"]), "test", "Verify handler response" );
 
 	// Trigger only the handlers (no native) and extra fn
 	// Triggers 8
-	equals( $("#firstp").triggerHandler("click", [1, "2", "abc"], handler), "test", "Verify handler response" );
+	equals( $("#firstp").triggerHandler("click", [1, "2", "abc"], handler2), "test", "Verify handler response" );
+
+	// Build fake click event to pass in
+	var eventObj = jQuery.event.fix({ type: "click", target: document.body });
+
+	// Trigger only the handlers (no native), with external event obj
+	// Triggers 5
+	equals( $("#firstp").triggerHandler("foo", [eventObj, 1, "2", "abc"]), "test", "Verify handler response" );
+
+	// Trigger only the handlers (no native) and extra fn, with external event obj
+	// Triggers 9
+	equals( $("#firstp").triggerHandler("foo", [eventObj, 1, "2", "abc"], handler), "test", "Verify handler response" );
 });
 
 test("toggle(Function, Function)", function() {