From c0d331675b8afae34873da3f08a63e861a7b785b Mon Sep 17 00:00:00 2001
From: Botond Ballo <botond@mozilla.com>
Date: Wed, 30 Jul 2014 15:11:20 -0400
Subject: [PATCH] Bug 1046013 - Fix APZ hit testing when root APZC is
 overscrolled and has siblings. r=kats

--HG--
extra : rebase_source : a2a0e143c70b3d8c2188ca281d2372d969d8c06b
---
 gfx/layers/apz/src/APZCTreeManager.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/gfx/layers/apz/src/APZCTreeManager.cpp b/gfx/layers/apz/src/APZCTreeManager.cpp
index 82de0f3010b..1d7c84c5d77 100644
--- a/gfx/layers/apz/src/APZCTreeManager.cpp
+++ b/gfx/layers/apz/src/APZCTreeManager.cpp
@@ -1026,7 +1026,9 @@ APZCTreeManager::GetTargetAPZC(const ScreenPoint& aPoint, bool* aOutInOverscroll
   bool inOverscrolledApzc = false;
   for (AsyncPanZoomController* apzc = mRootApzc; apzc; apzc = apzc->GetPrevSibling()) {
     target = GetAPZCAtPoint(apzc, point, &inOverscrolledApzc);
-    if (target) {
+    // If we hit an overscrolled APZC, 'target' will be nullptr but it's still
+    // a hit so we don't search further siblings.
+    if (target || inOverscrolledApzc) {
       break;
     }
   }