Re: wait_reading_process_ouput hangs in certain cases (w/ patches)

[andrés ramírez]

Hi Matthias

> I know what you are trying to say but in this particular case I think
> the risk is rather low of "breaking" someone's workflow. And if this
> change does introduce some kind of valid breakage, it would be nice
> to know about this sooner rather than later. I know 26 is already in
> beta, but this is essentially a bug fix and the recent patch is also
> smaller and more clearly laid-out which makes it easier to assess and
> reduces its side-effects.

I also think this patch is going to help with several cases and also
bugs difficult to fix or repeat.

> > Btw. Lars. Mentioned a hang. I have also got a hang a few minutes ago 
> > reading
> > nntp news with an specific site
> 
> Do you get those hangs with an Emacs version that had the bug fix?

Yes.

> have you been able to pinpoint where exactly Emacs hangs? (backtrace)
> Also, is this a "cancelable" hang (hitting ctrl+g) or a real hang and
> you need to kill Emacs altogether?
It is|was cancelable. On emacs 26 I used to use a workaround:
--8<---------------cut here---------------start------------->8---
(maphash
 (lambda (con &rest ignored)
         (when (and con (get-process (car con)))
                 (delete-process (car con))))
 url-http-open-connections)
--8<---------------cut here---------------end--------------->8---

On master (with the patch included) the var url-http-open-connections is
not present. With emacs-26 After applying the mentiode above workaround
 I could have restarted downloading news again .

Also on master. I need to restart wanderlust to continue downloading
news. If I do not restart wanderlust and I keep refreshing the news for
the site emacs hangs again and again needing C-g.

Question: I am going to see how to plug gdb to this server-session. Btw
how were You able of debugging It?. I was not able of doing It in the
last years.