landing patch for bug 237586 "Implement negotiateauth using SSPI for Windows" r=cneberg sr=bryner a=shaver

git-svn-id: svn://10.0.0.236/trunk@178018 18797224-902f-48f8-a5cc-f745e15eee43

mozilla/extensions/auth/nsAuthGSSAPI.cpp

@@ -217,10 +217,13 @@ nsNegotiateAuth::GetNextToken(const void *inToken,
         in_token_ptr = &input_token;
     }
     else if (mCtx != GSS_C_NO_CONTEXT) {
-        //
-        // Possibly starting over, clear out any existing context.
-        //
-        Reset();
+        // If there is no input token, then we are starting a new
+        // authentication sequence.  If we have already initialized our
+        // security context, then we're in trouble because it means that the
+        // first sequence failed.  We need to bail or else we might end up in
+        // an infinite loop.
+        LOG(("Cannot restart authentication sequence!"));
+        return NS_ERROR_UNEXPECTED; 
     }
 
 #if defined(XP_MACOSX)