Subject: Re: bug#14473: 24.3; emacs locks up when eshell attempts to display a dialog

From: Joseph Mingrone <[email-masked]>
Date: Thu, 03 Oct 2019 12:48:57 -0300

Eli Zaretskii <[email-masked]> writes:

>> From: Stefan Kangas <[email-masked]>
>> Date: Mon, 30 Sep 2019 17:47:48 +0200
>> Cc: [email-masked]

>> Joseph Mingrone <[email-masked]> writes:

>> > When working in Eshell, if a dialog such as
>> > http://www.freebsd.org/doc/en/books/handbook/install/dist-set2.png is to
>> > be displayed, Emacs will lock up and the processor will stay at 100%
>> > until Emacs is killed.  This also happens when starting with Emacs -Q.

>> Are you still seeing this on a modern version of Emacs?  If yes, could
>> you please provide a recipe for how to reproduce it, starting from
>> "emacs -Q"?

>> (BTW, the link above is dead.)

> You can still find it in the Internet Archive:

>   https://web.archive.org/web/20130801011654/http://www.freebsd.org/doc/en/books/handbook/install/dist-set2.png

It's still a problem (26.3 and 2019-09-15 master-branch build) in that the dialog is not displayed, but the Emacs process no longer consumes 100% CPU.

Here is a simple recipe to reproduce the problem.  It assumes the FreeBSD ports tree is installed in the default location, which is /usr/ports.

1. emacs -Q
2. M-x eshell
3. cd /usr/ports/editors/emacs
4. sudo make config

Instead of the dialog displaying, eshell becomes unusable (blank screen and no keys will return the prompt).  Trying to exit by hitting TAB/Enter reports

Completion function pcomplete-completions-at-point uses a deprecated calling convention
Warning: pcomplete-completions-at-point failed to return valid completion data!

You can switch buffers and kill the eshell process now though.