--- a/dom/base/nsGlobalWindow.cpp
+++ b/dom/base/nsGlobalWindow.cpp
@@ -9329,21 +9329,23 @@ nsGlobalWindow::ReallyCloseWindow()
            to destroy the container as it should but is a final measure
            to prevent an errant tab from doing so when it shouldn't.
            This works because we reach this code when we shouldn't only
            in the particular circumstance that we belong to a tab
            that has just been closed (and is therefore already missing
            from the list of browsers) (and has an unload handler
            that closes the window). */
         // XXXbz now that we have mHavePendingClose, is this needed?
-        bool isTab = false;
+        bool isTab;
         if (rootWin == AsOuter() ||
-            !bwin || (bwin->IsTabContentWindow(GetOuterWindowInternal(),
-                                               &isTab), isTab))
+            !bwin ||
+            (NS_SUCCEEDED(bwin->IsTabContentWindow(GetOuterWindowInternal(),
+                                                   &isTab)) && isTab)) {
           treeOwnerAsWin->Destroy();
+        }
       }
     }
 
     CleanUp();
   }
 }
 
 void

--- a/dom/xml/nsXMLFragmentContentSink.cpp
+++ b/dom/xml/nsXMLFragmentContentSink.cpp
@@ -1,13 +1,14 @@
 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
 #include "nsCOMPtr.h"
 #include "nsXMLContentSink.h"
 #include "nsIFragmentContentSink.h"
 #include "nsIXMLContentSink.h"
 #include "nsContentSink.h"
 #include "nsIExpatSink.h"
 #include "nsIDTD.h"
 #include "nsIDocument.h"
@@ -219,17 +220,17 @@ nsXMLFragmentContentSink::CreateElement(
   return rv;
 }
 
 nsresult
 nsXMLFragmentContentSink::CloseElement(nsIContent* aContent)
 {
   // don't do fancy stuff in nsXMLContentSink
   if (mPreventScriptExecution &&
-      (aContent->IsHTMLElement(nsGkAtoms::script),
+      (aContent->IsHTMLElement(nsGkAtoms::script) ||
        aContent->IsSVGElement(nsGkAtoms::script))) {
     nsCOMPtr<nsIScriptElement> sele = do_QueryInterface(aContent);
     if (sele) {
       sele->PreventExecution();
     } else {
       NS_ASSERTION(nsNameSpaceManager::GetInstance()->mSVGDisabled, "Script did QI correctly, but wasn't a disabled SVG!");
     }
   }