Bug 493266 - Optimize setting currentTarget, r+sr=bz

content/events/src/nsEventDispatcher.cpp

@@ -218,15 +218,14 @@ nsEventTargetChainItem::HandleEvent(nsEventChainPostVisitor& aVisitor,
     mTarget->GetListenerManager(PR_FALSE, getter_AddRefs(mManager));
   }
   if (mManager) {
-    nsPIDOMEventTarget* currentTarget = CurrentTarget()->GetTargetForDOMEvent();
-    aVisitor.mEvent->currentTarget = currentTarget;
-    if (aVisitor.mEvent->currentTarget) {
-      mManager->HandleEvent(aVisitor.mPresContext, aVisitor.mEvent,
-                            &aVisitor.mDOMEvent,
-                            currentTarget, aFlags,
-                            &aVisitor.mEventStatus);
-      aVisitor.mEvent->currentTarget = nsnull;
-    }
+    NS_ASSERTION(aVisitor.mEvent->currentTarget == nsnull,
+                 "CurrentTarget should be null!");
+    mManager->HandleEvent(aVisitor.mPresContext, aVisitor.mEvent,
+                          &aVisitor.mDOMEvent,
+                          CurrentTarget(), aFlags,
+                          &aVisitor.mEventStatus);
+    NS_ASSERTION(aVisitor.mEvent->currentTarget == nsnull,
+                 "CurrentTarget should be null!");
   }
   return NS_OK;
 }

content/events/src/nsEventListenerManager.cpp

@@ -1176,6 +1176,12 @@ found:
                                            EmptyString(), aDOMEvent);
           }
           if (*aDOMEvent) {
+            if (!aEvent->currentTarget) {
+              aEvent->currentTarget = aCurrentTarget->GetTargetForDOMEvent();
+              if (!aEvent->currentTarget) {
+                break;
+              }
+            }
             nsRefPtr<nsIDOMEventListener> kungFuDeathGrip = ls->mListener;
             if (useTypeInterface) {
               pusher.Pop();
@@ -1192,6 +1198,8 @@ found:
     }
   }
 
+  aEvent->currentTarget = nsnull;
+
   if (!hasListener) {
     mNoListenerForEvent = aEvent->message;
     mNoListenerForEventAtom = aEvent->userType;