Re: emacs-26 b3e2073 4/4: Fix subproc listening when setting filter to non-t (Bug#36591)

[Michael Albinus <michael.albinus@gmx.de>]

npostavs@gmail.com (Noam Postavsky) writes:

Hi Noam,

> --- a/test/src/process-tests.el
> +++ b/test/src/process-tests.el
> @@ -144,6 +144,35 @@
>      (should (equal "hello stderr!\n"
>  		   (mapconcat #'identity (nreverse stderr-output) "")))))
>
> +(ert-deftest set-process-filter-t ()
> +  "Test setting process filter to t and back." ;; Bug#36591
> +  (with-temp-buffer
> +    (let* ((print-level nil)
> +           (print-length nil)
> +           (proc (start-process
> +                  "test proc" (current-buffer)
> +                  (concat invocation-directory invocation-name)
> +                  "-Q" "--batch" "--eval"
> +                  (prin1-to-string
> +                   '(let (s)
> +                      (while (setq s (read-from-minibuffer "$ "))
> +                        (princ s)
> +                        (princ "\n")))))))
> +      (set-process-query-on-exit-flag proc nil)
> +      (send-string proc "one\n")
> +      (should
> +       (accept-process-output proc 1))  ; Read "one".
> +      (should (equal (buffer-string) "$ one\n$ "))
> +      (set-process-filter proc t)       ; Stop reading from proc.
> +      (send-string proc "two\n")
> +      (should-not
> +       (accept-process-output proc 1))  ; Can't read "two" yet.
> +      (should (equal (buffer-string) "$ one\n$ "))
> +      (set-process-filter proc nil)     ; Resume reading from proc.
> +      (should
> +       (accept-process-output proc 1))  ; Read "two" from proc.
> +      (should (equal (buffer-string) "$ one\n$ two\n$ ")))))

This fails on emba occasionally, see for example
<https://emba.gnu.org/emacs/emacs/-/jobs/3076>.

Best regards, Michael.