From 1fd6b4e56bd6f0e50c662bdeff744f49a9d9c70f Mon Sep 17 00:00:00 2001
From: "darin%meer.net" <darin%meer.net>
Date: Thu, 4 Nov 2004 02:34:11 +0000
Subject: [PATCH] fixes bug 234620 "Unknown random SEGV/seg fault/core
 dumps/crashes, only thing on is Mail/IMAP" r=dbaron sr=bienvenu

---
 xpcom/threads/nsEventQueue.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/xpcom/threads/nsEventQueue.cpp b/xpcom/threads/nsEventQueue.cpp
index 7dc8f08951d..3056a47233a 100644
--- a/xpcom/threads/nsEventQueue.cpp
+++ b/xpcom/threads/nsEventQueue.cpp
@@ -219,8 +219,11 @@ nsEventQueueImpl::StopAcceptingEvents()
 void
 nsEventQueueImpl::NotifyObservers(const char *aTopic)
 {
-  nsresult rv;
+  // we must not invoke the observer service from a background thread!
+  if (!nsIThread::IsMainThread())
+    return;
 
+  nsresult rv;
   nsCOMPtr<nsIObserverService> os = do_GetService("@mozilla.org/observer-service;1", &rv);
   if (NS_SUCCEEDED(rv)) {
     nsCOMPtr<nsIEventQueue> kungFuDeathGrip(this);