Remove the relatedTarget adjustment for mouseenter/leave events, it's an...

Remove the relatedTarget adjustment for mouseenter/leave events, it's an ambiguous case anyway and it is expensive to do.

src/event.js

@@ -699,8 +699,7 @@ jQuery.Event.prototype = {
 	isImmediatePropagationStopped: returnFalse
 };
 
-// Create mouseenter and mouseleave events; IE has its own native ones but
-// we need to support event delegation as well so we don't use them.
+// Create mouseenter/leave events using mouseover/out and event-time checks
 jQuery.each({
 	mouseenter: "mouseover",
 	mouseleave: "mouseout"
@@ -716,12 +715,9 @@ jQuery.each({
 				selector = handleObj.selector,
 				oldType, ret;
 
+			// For a real mouseover/out, always call the handler; for
+			// mousenter/leave call the handler if related is outside the target.
 			// NB: No relatedTarget if the mouse left/entered the browser window
-			if ( selector && related ) {
-				// Delegated event; find the real relatedTarget
-				related = jQuery( related ).closest( selector )[0];
-			}
-			// For mouseover/out, contains isn't needed; handle() already determined it's the right target
 			if ( !related || handleObj.origType === event.type || (related !== target && !jQuery.contains( target, related )) ) {
 				oldType = event.type;
 				event.type = handleObj.origType;

test/hovertest.html

@@ -44,8 +44,7 @@ p {
         	Mouse over here should NOT trigger the counter.
     	</div>
 	</div>
-
-	<div id="livebox" class="hover-box">
+	<div id="liveenterbox" class="hover-box">
     	<div class="hover-status">
 			<button>Activate</button>
 			Live enter/leave: <span class="ins">0</span> / <span class="outs">0</span>
@@ -54,7 +53,6 @@ p {
         	Mouse over here should NOT trigger the counter.
     	</div>
 	</div>
-
 	<div id="delegateenterbox" class="hover-box">
     	<div class="hover-status">
 			<button>Activate</button>
@@ -74,6 +72,15 @@ p {
         	Mouse over here SHOULD trigger the counter.
     	</div>
 	</div>
+	<div id="liveoverbox" class="hover-box">
+    	<div class="hover-status">
+			<button>Activate</button>
+			Live over/out: <span class="ins">0</span> / <span class="outs">0</span>
+		</div>
+    	<div class="hover-inside">
+        	Mouse over here SHOULD trigger the counter.
+    	</div>
+	</div>
 	<div id="delegateoverbox" class="hover-box">
     	<div class="hover-status">
 			<button>Activate</button>
@@ -115,8 +122,8 @@ $(function(){
 			.delegate("#delegateenterbox", "mouseleave", countOuts );
 		$(this).remove();
 	});
-	$("#livebox button").click(function(){
-		$("#livebox")
+	$("#liveenterbox button").click(function(){
+		$("#liveenterbox")
 			.data({ ins: 0, outs: 0 })
 			.live("mouseenter", countIns )
 			.live("mouseleave", countOuts );
@@ -130,6 +137,13 @@ $(function(){
 			.bind("mouseout", countOuts );
 		$(this).remove();
 	});
+	$("#liveoverbox button").click(function(){
+		$("#liveoverbox")
+			.data({ ins: 0, outs: 0 })
+			.live("mouseover", countIns )
+			.live("mouseout", countOuts );
+		$(this).remove();
+	});
 	$("#delegateoverbox button").click(function(){
 		$(document)
 			.find("#delegateoverbox").data({ ins: 0, outs: 0 }).end()