From 187eaaee7f37ffffb92fa398d280abb527be6fa2 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Mon, 7 Mar 2016 13:20:07 -0800
Subject: [PATCH] Fix issue with narrowing exported variables

---
 src/compiler/checker.ts | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 9d05bc60c27..f18239d5e74 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -7165,12 +7165,11 @@ namespace ts {
             if (!leftmostIdentifier) {
                 return type;
             }
-            const leftmostSymbol = getResolvedSymbol(leftmostIdentifier);
-            if (!(leftmostSymbol.flags & SymbolFlags.Variable)) {
+            const declaration = getExportSymbolOfValueSymbolIfExported(getResolvedSymbol(leftmostIdentifier)).valueDeclaration;
+            if (!declaration || declaration.kind !== SyntaxKind.VariableDeclaration && declaration.kind !== SyntaxKind.Parameter && declaration.kind !== SyntaxKind.BindingElement) {
                 return type;
             }
-            const declaration = getDeclarationOfKind(leftmostSymbol, SyntaxKind.VariableDeclaration);
-            const top = declaration && getDeclarationContainer(declaration);
+            const top = getDeclarationContainer(declaration);
             const originalType = type;
             const nodeStack: { node: Node, child: Node }[] = [];
             let node: Node = reference;