From 93465bdae2af3cd8a940c4fa3d75e4f00d73d048 Mon Sep 17 00:00:00 2001
From: Nathan Shively-Sanders <nathansa@microsoft.com>
Date: Tue, 6 Jun 2017 14:11:01 -0700
Subject: [PATCH] Filter nullables after lifting union over spread

Previously, null/undefined were removed upfront, which is incorrect. Now
nullable types are removed with other non-primitives after union is
lifted over spread. This produces unions, which are larger, but more correct.
---
 src/compiler/checker.ts | 2 --
 1 file changed, 2 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 1cc91550dc0..82459d6afbe 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -7632,11 +7632,9 @@ namespace ts {
             if (left.flags & TypeFlags.Any || right.flags & TypeFlags.Any) {
                 return anyType;
             }
-            left = filterType(left, t => !(t.flags & TypeFlags.Nullable));
             if (left.flags & TypeFlags.Never) {
                 return right;
             }
-            right = filterType(right, t => !(t.flags & TypeFlags.Nullable));
             if (right.flags & TypeFlags.Never) {
                 return left;
             }