From f08f6067e8c86059ee868cb4eb3e0db72b6e0e77 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Mon, 15 Feb 2016 09:38:49 -0800
Subject: [PATCH] Display support for nullable types

---
 src/compiler/checker.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 4d930b35667..96c6642fb26 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -53,7 +53,6 @@ namespace ts {
         const allowSyntheticDefaultImports = typeof compilerOptions.allowSyntheticDefaultImports !== "undefined" ? compilerOptions.allowSyntheticDefaultImports : modulekind === ModuleKind.System;
         const strictNullChecks = compilerOptions.strictNullChecks;
 
-
         const emitResolver = createResolver();
 
         const undefinedSymbol = createSymbol(SymbolFlags.Property | SymbolFlags.Transient, "undefined");
@@ -1873,6 +1872,10 @@ namespace ts {
                     else if (type.flags & TypeFlags.Tuple) {
                         writeTupleType(<TupleType>type);
                     }
+                    else if (isNullableType(type)) {
+                        writeType(getNonNullableType(type), TypeFormatFlags.InElementType);
+                        writePunctuation(writer, SyntaxKind.QuestionToken);
+                    }
                     else if (type.flags & TypeFlags.UnionOrIntersection) {
                         writeUnionOrIntersectionType(<UnionOrIntersectionType>type, flags);
                     }