From 23c25b789f399ddcaaabc83e418caff1644b772d Mon Sep 17 00:00:00 2001
From: "Kearwood (Kip) Gilbert" <kgilbert@mozilla.com>
Date: Mon, 28 Apr 2014 14:51:00 -0400
Subject: [PATCH] Bug 1001237 - Don't return
 nsChangeHint_UpdatePostTransformOverflow in nsStyleDisplay::CalcDifference
 when a transform is added. r=dbaron

---
 layout/style/nsStyleStruct.cpp | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/layout/style/nsStyleStruct.cpp b/layout/style/nsStyleStruct.cpp
index 12592d5472a..c7192e48ba0 100644
--- a/layout/style/nsStyleStruct.cpp
+++ b/layout/style/nsStyleStruct.cpp
@@ -2524,8 +2524,14 @@ nsChangeHint nsStyleDisplay::CalcDifference(const nsStyleDisplay& aOther) const
     if (!mSpecifiedTransform != !aOther.mSpecifiedTransform ||
         (mSpecifiedTransform &&
          *mSpecifiedTransform != *aOther.mSpecifiedTransform)) {
-      NS_UpdateHint(hint, NS_CombineHint(nsChangeHint_UpdatePostTransformOverflow,
-                                         nsChangeHint_UpdateTransformLayer));
+      NS_UpdateHint(hint, nsChangeHint_UpdateTransformLayer);
+
+      if (mSpecifiedTransform &&
+          aOther.mSpecifiedTransform) {
+        NS_UpdateHint(hint, nsChangeHint_UpdatePostTransformOverflow);
+      } else {
+        NS_UpdateHint(hint, nsChangeHint_UpdateOverflow);
+      }
     }
 
     const nsChangeHint kUpdateOverflowAndRepaintHint =