From d87ef134d74761a019d1cc90f10462af1a3bdd4c Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Tue, 29 Nov 2005 01:07:12 +0000
Subject: [PATCH] Fix PR670 and
 test/Regression/Transforms/Mem2Reg/2005-11-28-Crash.ll

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@24508 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Analysis/Dominators.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/llvm/Analysis/Dominators.h b/include/llvm/Analysis/Dominators.h
index 9db52f608e5..f0d9a8e133c 100644
--- a/include/llvm/Analysis/Dominators.h
+++ b/include/llvm/Analysis/Dominators.h
@@ -311,6 +311,7 @@ public:
     ///
     bool properlyDominates(const Node *N) const {
       const Node *IDom;
+      if (this == 0 || N == 0) return false;
       while ((IDom = N->getIDom()) != 0 && IDom != this)
         N = IDom;   // Walk up the tree
       return IDom != 0;