From 342fb612085b6e294eb9eb166f26617f8a35bde8 Mon Sep 17 00:00:00 2001
From: Jay McCarthy <jay@racket-lang.org>
Date: Mon, 23 Nov 2009 17:20:41 +0000
Subject: [PATCH] There is a race condition in this code. This doesn't totally
 fix it, if another process is creating and deleting the directory quickly,
 but it will help.

svn: r16996
---
 collects/scheme/file.ss | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/collects/scheme/file.ss b/collects/scheme/file.ss
index 624746de0c..6075feccb4 100644
--- a/collects/scheme/file.ss
+++ b/collects/scheme/file.ss
@@ -65,7 +65,13 @@
                (not (directory-exists? base)))
       (make-directory* base))
     (unless (directory-exists? dir)
-      (make-directory dir))))
+      (with-handlers ([exn:fail:filesystem?
+                       (lambda (x)
+                         (unless (and (regexp-match #rx"cannot make directory:.+File exists"
+                                                    (exn-message x))
+                                      (directory-exists? dir))
+                           (raise x)))])
+        (make-directory dir)))))
 
 (define (make-temporary-file [template "mztmp~a"] [copy-from #f] [base-dir #f])
   (with-handlers ([exn:fail:contract?