From fc36267f6f2ccb74f9a0fd139553641aa2b2a308 Mon Sep 17 00:00:00 2001
From: Chris Hanson <org/chris-hanson/cph>
Date: Thu, 27 May 2004 16:06:31 +0000
Subject: [PATCH] When closing a port, don't try to flush output if the channel
 is already closed.

---
 v7/src/runtime/genio.scm | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/v7/src/runtime/genio.scm b/v7/src/runtime/genio.scm
index bb88bbf8b..c53889b6d 100644
--- a/v7/src/runtime/genio.scm
+++ b/v7/src/runtime/genio.scm
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Id: genio.scm,v 1.31 2004/05/26 15:19:53 cph Exp $
+$Id: genio.scm,v 1.32 2004/05/27 16:06:31 cph Exp $
 
 Copyright 1991,1993,1995,1996,1999,2002 Massachusetts Institute of Technology
 Copyright 2003,2004 Massachusetts Institute of Technology
@@ -718,8 +718,10 @@ USA.
   (channel-open? (output-buffer-channel ob)))
 
 (define (close-output-buffer ob)
-  (force-drain-output-buffer ob)
-  (channel-close (output-buffer-channel ob)))
+  (if (output-buffer-open? ob)
+      (begin
+	(force-drain-output-buffer ob)
+	(channel-close (output-buffer-channel ob)))))
 
 (define-integrable (output-buffer-port ob)
   (channel-port (output-buffer-channel ob)))
-- 
2.25.1