Bug 836951 - If piwin is null, return NS_OK and skip setting the mixed content state. r=bsmith

security/manager/boot/src/nsSecureBrowserUIImpl.cpp

@@ -287,7 +287,8 @@ nsSecureBrowserUIImpl::MapInternalToExternalState(uint32_t* aState, lockIconStat
     *aState |= nsIWebProgressListener::STATE_IDENTITY_EV_TOPLEVEL;
 
   nsCOMPtr<nsPIDOMWindow> piwin = do_QueryReferent(mWindow);
-  MOZ_ASSERT(piwin);
+  if (!piwin)
+    return NS_OK;
 
   nsIDocShell* docShell = piwin->GetDocShell();
   MOZ_ASSERT(docShell);