From a69f8cc71bd1c56d651a76fed02f12a464b9610b Mon Sep 17 00:00:00 2001
From: Kashav Madan <kshvmdn@gmail.com>
Date: Thu, 25 Mar 2021 15:59:50 +0000
Subject: [PATCH] Bug 1700719 - Discard-check both the top-level and current
 context before restoring, r=nika

Differential Revision: https://phabricator.services.mozilla.com/D109722
---
 docshell/base/CanonicalBrowsingContext.cpp | 2 ++
 dom/ipc/WindowGlobalParent.cpp             | 6 +++---
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/docshell/base/CanonicalBrowsingContext.cpp b/docshell/base/CanonicalBrowsingContext.cpp
index 9fc299b21358..91d5fe9c963c 100644
--- a/docshell/base/CanonicalBrowsingContext.cpp
+++ b/docshell/base/CanonicalBrowsingContext.cpp
@@ -1745,6 +1745,8 @@ void CanonicalBrowsingContext::SetRestoreData(SessionStoreRestoreData* aData) {
 
 void CanonicalBrowsingContext::RequestRestoreTabContent(
     WindowGlobalParent* aWindow) {
+  MOZ_DIAGNOSTIC_ASSERT(IsTop());
+
   if (IsDiscarded() || !mRestoreData || mRestoreData->IsEmpty()) {
     return;
   }
diff --git a/dom/ipc/WindowGlobalParent.cpp b/dom/ipc/WindowGlobalParent.cpp
index 80642ffaee2f..bcc832f14be0 100644
--- a/dom/ipc/WindowGlobalParent.cpp
+++ b/dom/ipc/WindowGlobalParent.cpp
@@ -1294,9 +1294,9 @@ mozilla::ipc::IPCResult WindowGlobalParent::RecvResetSessionStore(
 }
 
 mozilla::ipc::IPCResult WindowGlobalParent::RecvRequestRestoreTabContent() {
-  CanonicalBrowsingContext* bc = BrowsingContext()->Top();
-  if (bc && !bc->IsDiscarded()) {
-    bc->RequestRestoreTabContent(this);
+  CanonicalBrowsingContext* bc = BrowsingContext();
+  if (bc && bc->AncestorsAreCurrent()) {
+    bc->Top()->RequestRestoreTabContent(this);
   }
   return IPC_OK();
 }