bug 95688 - check for null base url, possibly fixing talkback reported errors, sr=kin, r=alexsavulov

git-svn-id: svn://10.0.0.236/branches/MOZILLA_0_9_4_BRANCH@102408 18797224-902f-48f8-a5cc-f745e15eee43

mozilla/layout/html/document/src/nsFrameFrame.cpp

@@ -1190,6 +1190,8 @@ nsHTMLFrameInnerFrame::DoLoadURL(nsIPresContext* aPresContext)
         doc->GetBaseURL(*getter_AddRefs(baseURL));
       }
     }
+    if (!baseURL) return NS_ERROR_NULL_POINTER;
+
     nsAutoString absURL;
     rv = NS_MakeAbsoluteURI(absURL, url, baseURL);
     NS_ENSURE_SUCCESS(rv, rv);