From 21a67525e5238ed443cb748dc2f4e04c14ef1abb Mon Sep 17 00:00:00 2001
From: "heikki%netscape.com"
 <heikki%netscape.com@18797224-902f-48f8-a5cc-f745e15eee43>
Date: Sat, 29 Sep 2001 00:30:03 +0000
Subject: [PATCH] Bug 101429, bad argument to function, fixes assertion and
 potential crash. r=harishd, sr=hewitt.

git-svn-id: svn://10.0.0.236/trunk@104177 18797224-902f-48f8-a5cc-f745e15eee43
---
 .../extensions/inspector/base/src/inLayoutUtils.cpp  | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/mozilla/extensions/inspector/base/src/inLayoutUtils.cpp b/mozilla/extensions/inspector/base/src/inLayoutUtils.cpp
index c34d75b37cb..97287a89bd0 100644
--- a/mozilla/extensions/inspector/base/src/inLayoutUtils.cpp
+++ b/mozilla/extensions/inspector/base/src/inLayoutUtils.cpp
@@ -342,13 +342,17 @@ inLayoutUtils::GetSubDocumentFor(nsIDOMNode* aNode)
     nsCOMPtr<nsIPresShell> shell;
     doc->GetShellAt(0, getter_AddRefs(shell));
     if (shell) {
-      nsCOMPtr<nsIPresShell> subShell;
-      shell->GetSubShellFor(content, getter_AddRefs(subShell));
-      if (!subShell) return nsnull;
+      nsCOMPtr<nsISupports> supports;
+      shell->GetSubShellFor(content, getter_AddRefs(supports));
+      nsCOMPtr<nsIDocShell> docShell = do_QueryInterface(supports);
+      if (!docShell) 
+        return nsnull;
 
-      nsCOMPtr<nsIDocShell> docShell = do_QueryInterface(subShell);
       nsCOMPtr<nsIContentViewer> contentViewer;
       docShell->GetContentViewer(getter_AddRefs(contentViewer));
+      if (!contentViewer) 
+        return nsnull;
+
       nsCOMPtr<nsIDOMDocument> domdoc;
       contentViewer->GetDOMDocument(getter_AddRefs(domdoc));
       return domdoc;