mirrors/emacs
1
Fork 0
mirror of git://git.sv.gnu.org/emacs.git synced 2025-12-15 10:30:25 -08:00
Code Issues Projects Releases Wiki Activity

When closing an Eshell process target, send EOF three times

Browse source 
* lisp/eshell/esh-io.el (eshell-close-target): Send EOF 3 times.

* test/lisp/eshell/em-extpipe-tests.el (em-extpipe-tests--deftest):
Re-enable these tests on EMBA.

This patch is adapted by one from Ken Brown, who uncovered the reason
for this bug (bug#56025).
This commit is contained in:
Jim Porter 2022-06-26 18:27:20 +02:00 • committed by Lars Ingebrigtsen
parent 51f24fe2f4
commit 7faea4a15e
2 changed files with 14 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

16
lisp/eshell/esh-io.el
View file

@ -276,8 +276,20 @@ STATUS should be non-nil on successful termination of the output."
;; If we're redirecting to a process (via a pipe, or process
;; redirection), send it EOF so that it knows we're finished.
((eshell-processp target)
(if (eq (process-status target) 'run)
(process-send-eof target)))
;; According to POSIX.1-2017, section 11.1.9, sending EOF causes
;; all bytes waiting to be read to be sent to the process
;; immediately. Thus, if there are any bytes waiting, we need to
;; send EOF twice: once to flush the buffer, and a second time to
;; cause the next read() to return a size of 0, indicating
;; end-of-file to the reading process. However, some platforms
;; (e.g. Solaris) actually require sending a *third* EOF. Since
;; sending extra EOFs while the process is running shouldn't break
;; anything, we'll just send the maximum we'd ever need. See
;; bug#56025 for further details.
(let ((i 0))
(while (and (<= (cl-incf i) 3)
(eq (process-status target) 'run))
(process-send-eof target))))
;; A plain function redirection needs no additional arguments
;; passed.