From: Chris Hanson <org/chris-hanson/cph>
Date: Mon, 13 May 1996 05:01:11 +0000 (+0000)
Subject: Fix bug: reading output from a subprocess would occasionally signal an
X-Git-Tag: 20090517-FFI~5526
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=2a1da6179ac93ce047e185c8345ca8c90a140ac2;p=mit-scheme.git

Fix bug: reading output from a subprocess would occasionally signal an
error because the subprocess output channel was closed by Scheme when
it detected that the subprocess had closed the other end of the pipe.
However, the "output-copier" loop continued to operate assuming that
the channel was open.
---

diff --git a/v7/src/edwin/process.scm b/v7/src/edwin/process.scm
index 844dc660a..c769f0517 100644
--- a/v7/src/edwin/process.scm
+++ b/v7/src/edwin/process.scm
@@ -1,6 +1,6 @@
 ;;; -*-Scheme-*-
 ;;;
-;;;	$Id: process.scm,v 1.43 1996/05/12 07:13:03 cph Exp $
+;;;	$Id: process.scm,v 1.44 1996/05/13 05:01:11 cph Exp $
 ;;;
 ;;;	Copyright (c) 1991-96 Massachusetts Institute of Technology
 ;;;
@@ -689,9 +689,11 @@ after the listing is made.)"
 			       (loop))))))))))
 	  (channel-nonblocking channel)
 	  (let ((status (receiver copy-output)))
-	    (channel-blocking channel)
-	    (copy-output)
-	    (channel-close channel)
+	    (if (channel-open? channel)
+		(begin
+		  (channel-blocking channel)
+		  (copy-output)
+		  (channel-close channel)))
 	    status)))
       (receiver (lambda () unspecific))))