From 22e493d0d3f10697696ce6924c69dbc7e307ac7c Mon Sep 17 00:00:00 2001
From: Vladimir Matveev <vladima@microsoft.com>
Date: Mon, 1 Jun 2015 16:08:58 -0700
Subject: [PATCH] clean hostCache to avoid extending lifetime of script
 snapshots

---
 src/services/services.ts | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/services/services.ts b/src/services/services.ts
index 1019c5321929c..4e441e40d8777 100644
--- a/src/services/services.ts
+++ b/src/services/services.ts
@@ -2475,6 +2475,10 @@ module ts {
                 }
             }
 
+            // hostCache is captured in the closure for 'getOrCreateSourceFile' but it should not be used past this point.
+            // It needs to be cleared to allow all collected snapshots to be released
+            hostCache = undefined;
+
             program = newProgram;
 
             // Make sure all the nodes in the program are both bound, and have their parent 
@@ -2483,6 +2487,7 @@ module ts {
             return;
 
             function getOrCreateSourceFile(fileName: string): SourceFile {
+                Debug.assert(hostCache !== undefined);
                 // The program is asking for this file, check first if the host can locate it.
                 // If the host can not locate the file, then it does not exist. return undefined
                 // to the program to allow reporting of errors for missing files.