From 1905eac824e6f07f91279aefc65e5f3c52e90836 Mon Sep 17 00:00:00 2001
From: Daniel Rosenwasser <drosen@microsoft.com>
Date: Mon, 11 Jan 2016 12:22:40 -0800
Subject: [PATCH] Don't rely on truthiness.

---
 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 31ef24e537a..6e1c35a84dd 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -5636,7 +5636,7 @@ namespace ts {
              * See signatureAssignableTo, compareSignaturesIdentical
              */
             function signatureRelatedTo(source: Signature, target: Signature, reportErrors: boolean): Ternary {
-                return compareSignaturesRelated(source, target, /*ignoreReturnTypes*/ false, reportErrors && reportError, isRelatedTo);
+                return compareSignaturesRelated(source, target, /*ignoreReturnTypes*/ false, reportErrors ? reportError : undefined, isRelatedTo);
             }
 
             function signaturesIdenticalTo(source: Type, target: Type, kind: SignatureKind): Ternary {