diff --git a/mozilla/embedding/browser/webBrowser/nsWebBrowser.cpp b/mozilla/embedding/browser/webBrowser/nsWebBrowser.cpp
index 9eb97c822c6..8c8ad1a5fdb 100644
--- a/mozilla/embedding/browser/webBrowser/nsWebBrowser.cpp
+++ b/mozilla/embedding/browser/webBrowser/nsWebBrowser.cpp
@@ -79,6 +79,7 @@ static NS_DEFINE_CID(kLookAndFeelCID, NS_LOOKANDFEEL_CID);
 nsWebBrowser::nsWebBrowser() : mDocShellTreeOwner(nsnull), 
    mInitInfo(nsnull),
    mContentType(typeContentWrapper),
+   mActivating(PR_FALSE),
    mParentNativeWindow(nsnull),
    mProgressListener(nsnull),
    mBackgroundColor(0),
@@ -1605,6 +1606,13 @@ NS_IMETHODIMP nsWebBrowser::GetPrimaryContentWindow(nsIDOMWindowInternal **aDOMW
 /* void activate (); */
 NS_IMETHODIMP nsWebBrowser::Activate(void)
 {
+  // stop infinite recursion from windows with onfocus handlers that
+  // reactivate the window
+  if (mActivating)
+    return NS_OK;
+
+  mActivating = PR_TRUE;
+
   // try to set focus on the last focused window as stored in the
   // focus controller object.
   nsCOMPtr<nsIDOMWindow> domWindowExternal;
@@ -1664,6 +1672,7 @@ NS_IMETHODIMP nsWebBrowser::Activate(void)
     }
   }
 
+  mActivating = PR_FALSE;
   return NS_OK;
 }
 
diff --git a/mozilla/embedding/browser/webBrowser/nsWebBrowser.h b/mozilla/embedding/browser/webBrowser/nsWebBrowser.h
index 8b9e26d5b24..0746f9edd0d 100644
--- a/mozilla/embedding/browser/webBrowser/nsWebBrowser.h
+++ b/mozilla/embedding/browser/webBrowser/nsWebBrowser.h
@@ -137,6 +137,7 @@ protected:
    nsCOMPtr<nsIWindowWatcher> mWWatch;
    nsWebBrowserInitInfo*      mInitInfo;
    PRUint32                   mContentType;
+   PRBool                     mActivating;
    nativeWindow               mParentNativeWindow;
    nsIWebProgressListener    *mProgressListener;
    nsCOMPtr<nsIWebProgress>      mWebProgress;