POLL-PROCESS-FOR-OUTPUT must check the input channel to see if it is

there at all -- SUBPROCESS-DELETE will change the channel to #F.

diff --git a/v7/src/edwin/process.scm b/v7/src/edwin/process.scm
index 98a2ab9e21e676c173a5ad7ad71239f9146ace1d..aadb189348fb4e1d3e1bf0c51af34c25a49d41e0 100644 (file)
--- a/v7/src/edwin/process.scm
+++ b/v7/src/edwin/process.scm
@@ -1,6 +1,6 @@
 ;;; -*-Scheme-*-
 ;;;
-;;;    $Id: process.scm,v 1.32 1993/11/23 01:23:16 cph Exp $
+;;;    $Id: process.scm,v 1.33 1993/11/23 03:51:23 cph Exp $
 ;;;
 ;;;    Copyright (c) 1991-93 Massachusetts Institute of Technology
 ;;;
@@ -276,7 +276,8 @@ Initialized from the SHELL environment variable."
 (define (poll-process-for-output process)
   (let ((channel (process-input-channel process))
        (buffer (make-string 512)))
-    (and (channel-open? channel)
+    (and channel
+        (channel-open? channel)
         (let ((close-input
                (lambda ()
                  (deregister-process-input process)