From 93fa7341624e4735abcdf95811e47d79413a3822 Mon Sep 17 00:00:00 2001
From: Ryan Cavanaugh <RyanCavanaugh@users.noreply.github.com>
Date: Wed, 27 Feb 2019 14:33:25 -0800
Subject: [PATCH] Don't crash if someone created a folder while we were
 checking to see if it exists

---
 src/compiler/sys.ts | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/compiler/sys.ts b/src/compiler/sys.ts
index 33283c93803..6d8c4628092 100644
--- a/src/compiler/sys.ts
+++ b/src/compiler/sys.ts
@@ -615,7 +615,17 @@ namespace ts {
                 directoryExists,
                 createDirectory(directoryName: string) {
                     if (!nodeSystem.directoryExists(directoryName)) {
-                        _fs.mkdirSync(directoryName);
+                        // Wrapped in a try-catch to prevent crashing if we are in a race
+                        // with another copy of ourselves to create the same directory
+                        try {
+                            _fs.mkdirSync(directoryName);
+                        }
+                        catch (e) {
+                            if (e.code !== "EEXIST") {
+                                // Failed for some other reason (access denied?); still throw
+                                throw e;
+                            }
+                        }
                     }
                 },
                 getExecutingFilePath() {