Bug 1514762 - Delay modifying the observer list until we hit the even…

…t loop; r=smaug Differential Revision: https://phabricator.services.mozilla.com/D14830
mykmelez · Dec 19, 2018 · 330e681 · 330e681
1 parent 789f480
commit 330e681
Showing 1 changed file with 6 additions and 1 deletion.
diff --git a/dom/base/nsGlobalWindowOuter.cpp b/dom/base/nsGlobalWindowOuter.cpp
@@ -7265,7 +7265,12 @@ mozilla::dom::TabGroup* nsPIDOMWindowOuter::TabGroup() {
   window->InitWasOffline();
   nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
   if (obs) {
-    obs->AddObserver(window, PERM_CHANGE_NOTIFICATION, true);
+    // Delay calling AddObserver until we hit the event loop, in case we may be
+    // in the middle of modifying the observer list somehow.
+    NS_DispatchToMainThread(
+        NS_NewRunnableFunction("PermChangeDelayRunnable", [obs, window] {
+          obs->AddObserver(window, PERM_CHANGE_NOTIFICATION, true);
+        }));
   }
   nsCOMPtr<nsIPrefBranch> prefBranch = do_GetService(NS_PREFSERVICE_CONTRACTID);
   if (prefBranch) {