From a0ee1f3c0d9f17479e0688f1706353293261e46b Mon Sep 17 00:00:00 2001
From: Moonchild <moonchild@palemoon.org>
Date: Thu, 15 Jul 2021 04:11:48 +0000
Subject: [PATCH] [layout] Ensure we set the primary frame for native anon
 content where needed.

---
 layout/base/nsCSSFrameConstructor.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/layout/base/nsCSSFrameConstructor.cpp b/layout/base/nsCSSFrameConstructor.cpp
index 25a5e58108..df793c67f8 100644
--- a/layout/base/nsCSSFrameConstructor.cpp
+++ b/layout/base/nsCSSFrameConstructor.cpp
@@ -3463,8 +3463,10 @@ nsCSSFrameConstructor::ConstructTextFrame(const FrameConstructionData* aData,
   // Add the newly constructed frame to the flow
   aFrameItems.AddChild(newFrame);
 
-  if (!aState.mCreatingExtraFrames)
+  if (!aState.mCreatingExtraFrames ||
+      (aContent->IsInNativeAnonymousSubtree() && !aContent->GetPrimaryFrame())) {
     aContent->SetPrimaryFrame(newFrame);
+  }
 }
 
 /* static */