From c8338b2791099184e14c418750fc1be532b1ec18 Mon Sep 17 00:00:00 2001
From: "danm%netscape.com" <danm%netscape.com>
Date: Thu, 3 Jul 2003 21:13:01 +0000
Subject: [PATCH] active window must be a top-level docshell. bug 170693.
 r=blizzard,bryner

---
 .../components/windowwatcher/src/nsWindowWatcher.cpp      | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/embedding/components/windowwatcher/src/nsWindowWatcher.cpp b/embedding/components/windowwatcher/src/nsWindowWatcher.cpp
index ad930cfc899..17b47256a44 100644
--- a/embedding/components/windowwatcher/src/nsWindowWatcher.cpp
+++ b/embedding/components/windowwatcher/src/nsWindowWatcher.cpp
@@ -885,8 +885,12 @@ nsWindowWatcher::GetActiveWindow(nsIDOMWindow **aActiveWindow)
 NS_IMETHODIMP
 nsWindowWatcher::SetActiveWindow(nsIDOMWindow *aActiveWindow)
 {
-  mActiveWindow = aActiveWindow;
-  return NS_OK;
+  if (FindWindowEntry(aActiveWindow)) {
+    mActiveWindow = aActiveWindow;
+    return NS_OK;
+  }
+  NS_ERROR("invalid active window");
+  return NS_ERROR_FAILURE;
 }
 
 NS_IMETHODIMP