From 88fc415c69792e3919504c610924f83b5a6d4748 Mon Sep 17 00:00:00 2001
From: JamesP <jlp765@gmail.com>
Date: Sat, 12 Sep 2015 14:41:50 +1000
Subject: [PATCH] bug fix: close() only unmapViewOfFile() when fHandle is
 valid. Added extra test on windows close so if already closed it doesn't
 throw an exception.

---
 lib/pure/memfiles.nim | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/pure/memfiles.nim b/lib/pure/memfiles.nim
index 27b9895974..a8bfa14d30 100644
--- a/lib/pure/memfiles.nim
+++ b/lib/pure/memfiles.nim
@@ -226,7 +226,7 @@ proc close*(f: var MemFile) =
   var lastErr: OSErrorCode
 
   when defined(windows):
-    if f.fHandle != INVALID_HANDLE_VALUE:
+    if f.fHandle != INVALID_HANDLE_VALUE and f.fHandle != 0:
       error = unmapViewOfFile(f.mem) == 0
       lastErr = osLastError()
       error = (closeHandle(f.mapHandle) == 0) or error