From 83971d0900b48a6c88c287b154a2c74bdc6409d0 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Wed, 8 Jun 2016 10:51:32 -0700
Subject: [PATCH] Create intersection types in type guards for unrelated types

---
 src/compiler/checker.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 650bc488b0e..ea494725fc6 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -7997,7 +7997,7 @@ namespace ts {
                 const targetType = type.flags & TypeFlags.TypeParameter ? getApparentType(type) : type;
                 return isTypeAssignableTo(candidate, targetType) ? candidate :
                     isTypeAssignableTo(type, candidate) ? type :
-                    neverType;
+                    getIntersectionType([type, candidate]);
             }
 
             function narrowTypeByTypePredicate(type: Type, callExpression: CallExpression, assumeTrue: boolean): Type {