From e0ca9137b8fb8d176ba54073428ec739813c0073 Mon Sep 17 00:00:00 2001
From: simonmar <unknown>
Date: Fri, 25 Jan 2002 12:22:27 +0000
Subject: [PATCH] [project @ 2002-01-25 12:22:27 by simonmar] Fix tryTakeMVar
 - amazingly it only worked with an empty MVar, and this was
 the only case I tested.  oops.

Merge to stable.
---
 ghc/rts/PrimOps.hc |   11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/ghc/rts/PrimOps.hc b/ghc/rts/PrimOps.hc
index 083031a..d386f84 100644
--- a/ghc/rts/PrimOps.hc
+++ b/ghc/rts/PrimOps.hc
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: PrimOps.hc,v 1.87 2001/12/06 13:05:03 sewardj Exp $
+ * $Id: PrimOps.hc,v 1.88 2002/01/25 12:22:27 simonmar Exp $
  *
  * (c) The GHC Team, 1998-2000
  *
@@ -1163,19 +1163,18 @@ FN_(tryTakeMVarzh_fast)
       /* unlock in the SMP case */
       SET_INFO(mvar,&stg_FULL_MVAR_info);
 #endif
-      TICK_RET_UNBOXED_TUP(1);
-      RET_P(val);
   } else {
       /* No further putMVars, MVar is now empty */
+      mvar->value = (StgClosure *)&stg_END_TSO_QUEUE_closure;
 
       /* do this last... we might have locked the MVar in the SMP case,
        * and writing the info pointer will unlock it.
        */
       SET_INFO(mvar,&stg_EMPTY_MVAR_info);
-      mvar->value = (StgClosure *)&stg_END_TSO_QUEUE_closure;
-      TICK_RET_UNBOXED_TUP(1);
-      RET_P(val);
   }
+
+  TICK_RET_UNBOXED_TUP(1);
+  RET_NP((I_)1, val);
   FE_
 }
 
-- 
1.7.10.4