From 34d576d55d83a42f7fab6c0555631da781c320e5 Mon Sep 17 00:00:00 2001
From: "Matt A. Tobin" <email@mattatobin.com>
Date: Fri, 17 Apr 2020 05:25:20 -0400
Subject: [PATCH] Bug 1360157 - Assert that a display: contents child always
 has a parent

Tag #1375
---
 layout/base/nsCSSFrameConstructor.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/layout/base/nsCSSFrameConstructor.cpp b/layout/base/nsCSSFrameConstructor.cpp
index 866fa148bf..bee9ed6299 100644
--- a/layout/base/nsCSSFrameConstructor.cpp
+++ b/layout/base/nsCSSFrameConstructor.cpp
@@ -8296,6 +8296,7 @@ nsCSSFrameConstructor::ContentRemoved(nsIContent*  aContainer,
              "display:contents nodes shouldn't have a frame");
   if (!childFrame && GetDisplayContentsStyleFor(aChild)) {
     nsIContent* ancestor = aContainer;
+    MOZ_ASSERT(ancestor, "display: contents on the root?");
     while (!ancestor->GetPrimaryFrame()) {
       // FIXME(emilio): Should this use the flattened tree parent instead?
       ancestor = ancestor->GetParent();