From d06a39a730c4787d63adfb58959e3b84719fd4ef Mon Sep 17 00:00:00 2001
From: James Teh <jteh@mozilla.com>
Date: Mon, 28 Jul 2025 19:31:35 +0000
Subject: [PATCH] Bug 1977166: When moving a RemoteAccessible, ensure it
 doesn't still have a parent.  a=diannaS

Original Revision: https://phabricator.services.mozilla.com/D257206

Differential Revision: https://phabricator.services.mozilla.com/D258841
---
 accessible/ipc/DocAccessibleParent.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/accessible/ipc/DocAccessibleParent.cpp b/accessible/ipc/DocAccessibleParent.cpp
index d5230f1d324d..b9fce0a3228a 100644
--- a/accessible/ipc/DocAccessibleParent.cpp
+++ b/accessible/ipc/DocAccessibleParent.cpp
@@ -221,7 +221,11 @@ RemoteAccessible* DocAccessibleParent::CreateAcc(
   RemoteAccessible* newProxy;
   if ((newProxy = GetAccessible(aAccData.ID()))) {
     // This is a move. Reuse the Accessible; don't destroy it.
-    MOZ_ASSERT(!newProxy->RemoteParent());
+    if (newProxy->RemoteParent()) {
+      MOZ_ASSERT_UNREACHABLE(
+          "Attempt to move RemoteAccessible which still has a parent!");
+      return nullptr;
+    }
     return newProxy;
   }