From 7f9c0373aacaf59f30aa9f275dcace505c8d5d89 Mon Sep 17 00:00:00 2001
From: simonmar <unknown>
Date: Thu, 27 Oct 2005 08:00:03 +0000
Subject: [PATCH] [project @ 2005-10-27 08:00:03 by simonmar] Fix
 getThreadLocalVar() on Win32 - thanks for Krasimir for
 finding the bug.

---
 ghc/rts/win32/OSThreads.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/ghc/rts/win32/OSThreads.c b/ghc/rts/win32/OSThreads.c
index e4cd76b..5559765 100644
--- a/ghc/rts/win32/OSThreads.c
+++ b/ghc/rts/win32/OSThreads.c
@@ -137,9 +137,13 @@ getThreadLocalVar (ThreadLocalKey *key)
 {
     void *r;
     r = TlsGetValue(*key);
-    if (r == NULL) {
+#ifdef DEBUG
+    // r is allowed to be NULL - it can mean that either there was an
+    // error or the stored value is in fact NULL.
+    if (GetLastError() != NO_ERROR) {
 	barf("getThreadLocalVar: key not found");
     }
+#endif
     return r;
 }
 
-- 
1.7.10.4