From 57e5655e8a3157c4691bfab4a98af169a2aa11d5 Mon Sep 17 00:00:00 2001
From: wolfbeast <mcwerewolf@wolfbeast.com>
Date: Sat, 25 May 2019 16:08:16 +0200
Subject: Avoid some useless ForgetSkippable handling while we're already
 dealing with snow-white objects.

---
 xpcom/base/nsCycleCollector.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/xpcom/base/nsCycleCollector.cpp b/xpcom/base/nsCycleCollector.cpp
index 06ed42326..5dffa7409 100644
--- a/xpcom/base/nsCycleCollector.cpp
+++ b/xpcom/base/nsCycleCollector.cpp
@@ -2832,6 +2832,11 @@ nsCycleCollector::ForgetSkippable(bool aRemoveChildlessNodes,
 {
   CheckThreadSafety();
 
+  // Avoid this when we're aleady dealing with snow-white objects.
+  if (mFreeingSnowWhite) {
+    return;
+  }
+
   mozilla::Maybe<mozilla::AutoGlobalTimelineMarker> marker;
   if (NS_IsMainThread()) {
     marker.emplace("nsCycleCollector::ForgetSkippable", MarkerStackRequest::NO_STACK);
-- 
cgit v1.2.3