diff -r 000000000000 -r 6474c204b198 gfx/2d/unittest/TestBugs.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/2d/unittest/TestBugs.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,86 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "TestBugs.h"
+#include "2D.h"
+#include <string.h>
+
+using namespace mozilla;
+using namespace mozilla::gfx;
+
+TestBugs::TestBugs()
+{
+  REGISTER_TEST(TestBugs, CairoClip918671);
+  REGISTER_TEST(TestBugs, PushPopClip950550);
+}
+
+void
+TestBugs::CairoClip918671()
+{
+  RefPtr<DrawTarget> dt = Factory::CreateDrawTarget(BackendType::CAIRO,
+                                                    IntSize(100, 100),
+                                                    SurfaceFormat::B8G8R8A8);
+  RefPtr<DrawTarget> ref = Factory::CreateDrawTarget(BackendType::CAIRO,
+                                                     IntSize(100, 100),
+                                                     SurfaceFormat::B8G8R8A8);
+  // Create a path that extends around the center rect but doesn't intersect it.
+  RefPtr<PathBuilder> pb1 = dt->CreatePathBuilder();
+  pb1->MoveTo(Point(10, 10));
+  pb1->LineTo(Point(90, 10));
+  pb1->LineTo(Point(90, 20));
+  pb1->LineTo(Point(10, 20));
+  pb1->Close();
+  pb1->MoveTo(Point(90, 90));
+  pb1->LineTo(Point(91, 90));
+  pb1->LineTo(Point(91, 91));
+  pb1->LineTo(Point(91, 90));
+  pb1->Close();
+
+  RefPtr<Path> path1 = pb1->Finish();
+  dt->PushClip(path1);
+
+  // This center rect must NOT be rectilinear!
+  RefPtr<PathBuilder> pb2 = dt->CreatePathBuilder();
+  pb2->MoveTo(Point(50, 50));
+  pb2->LineTo(Point(55, 51));
+  pb2->LineTo(Point(54, 55));
+  pb2->LineTo(Point(50, 56));
+  pb2->Close();
+
+  RefPtr<Path> path2 = pb2->Finish();
+  dt->PushClip(path2);
+
+  dt->FillRect(Rect(0, 0, 100, 100), ColorPattern(Color(1,0,0)));
+
+  RefPtr<SourceSurface> surf1 = dt->Snapshot();
+  RefPtr<SourceSurface> surf2 = ref->Snapshot();
+
+  RefPtr<DataSourceSurface> dataSurf1 = surf1->GetDataSurface();
+  RefPtr<DataSourceSurface> dataSurf2 = surf2->GetDataSurface();
+
+  for (int y = 0; y < dt->GetSize().height; y++) {
+    VERIFY(memcmp(dataSurf1->GetData() + y * dataSurf1->Stride(),
+                  dataSurf2->GetData() + y * dataSurf2->Stride(),
+                  dataSurf1->GetSize().width * 4) == 0);
+  }
+
+}
+
+void
+TestBugs::PushPopClip950550()
+{
+  RefPtr<DrawTarget> dt = Factory::CreateDrawTarget(BackendType::CAIRO,
+                                                    IntSize(500, 500),
+                                                    SurfaceFormat::B8G8R8A8);
+  dt->PushClipRect(Rect(0, 0, 100, 100));
+  Matrix m(1, 0, 0, 1, 45, -100);
+  dt->SetTransform(m);
+  dt->PopClip();
+
+  // We fail the test if we assert in this call because our draw target's
+  // transforms are out of sync.
+  dt->FillRect(Rect(50, 50, 50, 50), ColorPattern(Color(0.5f, 0, 0, 1.0f)));
+}
+