From 3d862788905d3912826eacd5dfac25a8e3c20734 Mon Sep 17 00:00:00 2001
From: Lang Hames <lhames@gmail.com>
Date: Thu, 17 Mar 2016 20:35:00 +0000
Subject: [PATCH] [Support] Make Error::isA<T>() works on success values.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263745 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Support/Error.h    | 2 +-
 unittests/Support/ErrorTest.cpp | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/llvm/Support/Error.h b/include/llvm/Support/Error.h
index b0eaa44498f..33a3bc9404e 100644
--- a/include/llvm/Support/Error.h
+++ b/include/llvm/Support/Error.h
@@ -195,7 +195,7 @@ public:
 
   /// Check whether one error is a subclass of another.
   template <typename ErrT> bool isA() const {
-    return getPtr()->isA(ErrT::classID());
+    return getPtr() && getPtr()->isA(ErrT::classID());
   }
 
 private:
diff --git a/unittests/Support/ErrorTest.cpp b/unittests/Support/ErrorTest.cpp
index ed3d1c1852c..d5af2cab967 100644
--- a/unittests/Support/ErrorTest.cpp
+++ b/unittests/Support/ErrorTest.cpp
@@ -149,14 +149,17 @@ TEST(Error, CheckCustomErrors) {
   {
     Error E = make_error<CustomError>(1);
     Error F = make_error<CustomSubError>(1, 2);
+    Error G = Error::success();
 
     EXPECT_TRUE(E.isA<CustomError>());
     EXPECT_FALSE(E.isA<CustomSubError>());
     EXPECT_TRUE(F.isA<CustomError>());
     EXPECT_TRUE(F.isA<CustomSubError>());
+    EXPECT_FALSE(G.isA<CustomError>());
 
     consumeError(std::move(E));
     consumeError(std::move(F));
+    consumeError(std::move(G));
   }
 
   // Check that we can handle a custom error.