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 844dc660af22944f378e97b1eb051a9aab4a94ec..c769f0517006dd0220f3166694a5b5ce2780715e 100644 (file)
--- 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))))
 \f