Bug 289792. Make sure to use the correct (but stupid) reference view when translating event coordinates. Also, bulletproof nsViewManager to not rely on frames undoing event coordinate translations, in case we ever screw that up. r+sr=bzbarsky,a=asa

layout/base/nsPresShell.cpp

@@ -6345,7 +6345,9 @@ PresShell::HandleEventInternal(nsEvent* aEvent, nsIView *aView,
                        "How did GetCurrentEventFrame() succeed?");
           nsIView* rootView;
           mViewManager->GetRootView(rootView);
-          nsIView* frameView = mCurrentEventFrame->GetClosestView();
+          nsIView* frameView;
+          nsPoint pt;
+          mCurrentEventFrame->GetOffsetFromView(pt, &frameView);
           offset = frameView->GetOffsetTo(rootView) - offsetOfaView;
         }
 

layout/generic/nsBlockFrame.cpp

@@ -6541,10 +6541,11 @@ nsBlockFrame::HandleEvent(nsPresContext* aPresContext,
     if (resultFrame)
     {
       // Translate aEvent->point to resultFrame's closest view (bug 180015).
-      nsIView* closestView = GetClosestView();
-      nsIView* resultFrameView = resultFrame->GetClosestView();
-      if (closestView != resultFrameView && resultFrameView) {
-        aEvent->point -= resultFrameView->GetOffsetTo(closestView);
+      nsPoint tmp;
+      nsIView* resultFrameParentView;
+      resultFrame->GetOffsetFromView(tmp, &resultFrameParentView);
+      if (parentWithView != resultFrameParentView && resultFrameParentView) {
+        aEvent->point += resultFrameParentView->GetOffsetTo(parentWithView);
       }
 
       if (NS_POSITION_BEFORE_TABLE == result)

view/src/nsViewManager.cpp

@@ -2485,6 +2485,8 @@ nsEventStatus nsViewManager::HandleEvent(nsView* aView, nsGUIEvent* aEvent, PRBo
     }
   }
 
+  // Save aEvent->point because child code might change it
+  nsPoint pt = aEvent->point;
   for (i = 0; i < targetViews.Count(); i++) {
     DisplayListElement2* element = NS_STATIC_CAST(DisplayListElement2*, targetViews.ElementAt(i));
     nsView* v = element->mView;
@@ -2494,11 +2496,7 @@ nsEventStatus nsViewManager::HandleEvent(nsView* aView, nsGUIEvent* aEvent, PRBo
       nsRect r;
       v->GetDimensions(r);
 
-      nscoord x = element->mAbsX - r.x;
-      nscoord y = element->mAbsY - r.y;
-
-      aEvent->point.x -= x;
-      aEvent->point.y -= y;
+      aEvent->point = pt - (nsPoint(element->mAbsX, element->mAbsY) - r.TopLeft());
 
       nsViewManager* vVM = v->GetViewManager();
       if (vVM == this) {
@@ -2515,9 +2513,6 @@ nsEventStatus nsViewManager::HandleEvent(nsView* aView, nsGUIEvent* aEvent, PRBo
         }
       }
 
-      aEvent->point.x += x;
-      aEvent->point.y += y;
-
       if (handled) {
         break;
       }