From: Chris Hanson <org/chris-hanson/cph>
Date: Tue, 23 Nov 1993 01:23:16 +0000 (+0000)
Subject: BSD PTYs signal I/O-error when trying to read from a master side whose
X-Git-Tag: 20090517-FFI~7437
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=3046562891be05f269d040e47f45d7a8c2a24c90;p=mit-scheme.git

BSD PTYs signal I/O-error when trying to read from a master side whose
slave has been closed; SYSV PTYs return EOF in same case.  Add code to
handle BSD case (this code has a race in it but seems to work OK).
---

diff --git a/v7/src/edwin/process.scm b/v7/src/edwin/process.scm
index 528c452e6..98a2ab9e2 100644
--- a/v7/src/edwin/process.scm
+++ b/v7/src/edwin/process.scm
@@ -1,6 +1,6 @@
 ;;; -*-Scheme-*-
 ;;;
-;;;	$Id: process.scm,v 1.31 1993/09/10 19:12:52 cph Exp $
+;;;	$Id: process.scm,v 1.32 1993/11/23 01:23:16 cph Exp $
 ;;;
 ;;;	Copyright (c) 1991-93 Massachusetts Institute of Technology
 ;;;
@@ -277,16 +277,18 @@ Initialized from the SHELL environment variable."
   (let ((channel (process-input-channel process))
 	(buffer (make-string 512)))
     (and (channel-open? channel)
-	 (let ((n (channel-read channel buffer 0 512)))
-	   (cond ((not n)
-		  #f)
-		 ((> n 0)
-		  (output-substring process buffer n))
-		 (else
+	 (let ((close-input
+		(lambda ()
 		  (deregister-process-input process)
 		  (channel-close channel)
 		  (%update-global-notification-tick)
-		  (poll-process-for-status-change process)))))))
+		  (poll-process-for-status-change process))))
+	   (if (process-runnable? process)
+	       (let ((n (channel-read channel buffer 0 512)))
+		 (cond ((not n) #f)
+		       ((> n 0) (output-substring process buffer n))
+		       (else (close-input))))
+	       (close-input))))))
 
 (define (process-send-eof process)
   (process-send-char process #\EOT))