Bug 125386. Turn MOUSE_EXIT events into MOUSE_MOVEs when the mouse didn't actually leave the top level widget. r+sr=bzbarsky

content/events/src/nsEventStateManager.cpp

@@ -460,6 +460,22 @@ nsEventStateManager::PreHandleEvent(nsPresContext* aPresContext,
   case NS_MOUSE_MIDDLE_BUTTON_UP:
     SetClickCount(aPresContext, (nsMouseEvent*)aEvent, aStatus);
     break;
+  case NS_MOUSE_EXIT:
+    // If the event coordinate is within the bounds of the view,
+    // then it's not really an exit --- we may have traversed
+    // widget boundaries but we're still in our toplevel window.
+    if ((aView->GetBounds() - aView->GetPosition()).Contains(aEvent->point)) {
+      // treat it as a move so we don't generate spurious "exit"
+      // events Any necessary exit events will be generated by
+      // GenerateMouseEnterExit
+      aEvent->message = NS_MOUSE_MOVE;
+      // then fall through...
+    } else {
+      GenerateMouseEnterExit(aPresContext, (nsGUIEvent*)aEvent);
+      //This is a window level mouse exit event and should stop here
+      aEvent->message = 0;
+      break;
+    }
   case NS_MOUSE_MOVE:
     if (IsTrackingDragGesture() &&
         NS_STATIC_CAST(nsMouseEvent*, aEvent)->reason ==
@@ -482,11 +498,6 @@ nsEventStateManager::PreHandleEvent(nsPresContext* aPresContext,
     UpdateCursor(aPresContext, aEvent, mCurrentTarget, aStatus);
     GenerateMouseEnterExit(aPresContext, (nsGUIEvent*)aEvent);
     break;
-  case NS_MOUSE_EXIT:
-    GenerateMouseEnterExit(aPresContext, (nsGUIEvent*)aEvent);
-    //This is a window level mouseenter event and should stop here
-    aEvent->message = 0;
-    break;
 #ifdef CLICK_HOLD_CONTEXT_MENUS
   case NS_DRAGDROP_GESTURE:
     // an external drag gesture event came in, not generated internally

view/src/nsViewManager.cpp

@@ -2434,7 +2434,6 @@ nsEventStatus nsViewManager::HandleEvent(nsView* aView, nsGUIEvent* aEvent, PRBo
   // accessibility events and key events are dispatched directly to the focused view
   if (aEvent->eventStructType == NS_ACCESSIBLE_EVENT
       || aEvent->message == NS_CONTEXTMENU_KEY
-      || aEvent->message == NS_MOUSE_EXIT
       || NS_IS_KEY_EVENT(aEvent) || NS_IS_IME_EVENT(aEvent) || NS_IS_FOCUS_EVENT(aEvent)) {
     nsEventStatus status = nsEventStatus_eIgnore;
     if (obs) {
@@ -3598,7 +3597,7 @@ PRBool nsViewManager::CreateDisplayList(nsView *aView,
     if (isClipView) {
       aDamageRect = &irect;
     }
-    if (aEventProcessing && aRealView == aView) {
+    if (aEventProcessing && aTopView == aView) {
       // Always deliver an event somewhere, at least to the top-level target.
       // There may be mouse capturing going on.
       overlap = PR_TRUE;