From 693fff053b40919c4f7619bba45d16719568c76e Mon Sep 17 00:00:00 2001
From: Bas Schouten <bschouten@mozilla.com>
Date: Thu, 11 Feb 2016 22:15:11 +0100
Subject: [PATCH] Bug 1247380: Only copy the background if we can succesfully
 get a snapshot. r=jrmuizel

MozReview-Commit-ID: uWH7MtJmSp
---
 gfx/thebes/gfxContext.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/gfx/thebes/gfxContext.cpp b/gfx/thebes/gfxContext.cpp
index a3309268b25e..5961abdef44e 100644
--- a/gfx/thebes/gfxContext.cpp
+++ b/gfx/thebes/gfxContext.cpp
@@ -854,9 +854,11 @@ gfxContext::PushGroupAndCopyBackground(gfxContentType content, Float aOpacity, S
       mDT->PushLayer(content == gfxContentType::COLOR, aOpacity, aMask, aMaskTransform, IntRect(), false);
     }
   } else {
-    if (pushOpaqueWithCopiedBG) {
+    RefPtr<SourceSurface> source;
+    // This snapshot can be nullptr if the DrawTarget is a cairo target that is currently
+    // in an error state.
+    if (pushOpaqueWithCopiedBG && (source = mDT->Snapshot())) {
       DrawTarget *oldDT = mDT;
-      RefPtr<SourceSurface> source = mDT->Snapshot();
       Point oldDeviceOffset = CurrentState().deviceOffset;
 
       PushNewDT(gfxContentType::COLOR);