Subject: bug#72778: closed (Re: bug#72778: 31.0.50; Calc: g f doesn't display gnuplot window after closing)

From: [email-masked] (GNU bug Tracking System)
Date: Sat, 31 Aug 2024 10:02:02 +0000

Your bug report

#72778: 31.0.50; Calc: g f doesn't display gnuplot window after closing

which was filed against the emacs package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to [email-masked].

-- 
72778: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=72778
GNU Bug Tracking System
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Subject: Re: bug#72778: 31.0.50; Calc: g f doesn't display gnuplot window after closing
From: Eli Zaretskii <[email-masked]>
To: [email-masked], [email-masked], Visuwesh <[email-masked]>
Cc: [email-masked]
Date: Sat, 31 Aug 2024 13:00:50 +0300
List-Id: <debbugs-submit.debbugs.gnu.org>

> Cc: [email-masked], [email-masked]
> Date: Wed, 28 Aug 2024 15:39:21 +0300
> From: Eli Zaretskii <[email-masked]>
> 
> > Cc: [email-masked]
> > Date: Wed, 28 Aug 2024 11:01:48 +0200
> > From:  Michael Heerdegen via "Bug reports for GNU Emacs,
> >  the Swiss army knife of text editors" <[email-masked]>
> > 
> > Pip Cet <[email-masked]> writes:
> > 
> > > [...]
> > > I've submitted a patch to gnuplot to fix these issues, but a workaround
> > > is required for, at least, existing gnuplot versions.  Sending an extra
> > > newline character preceding each gnuplot command, as Visuwesh's patch
> > > does, should be both safe and effective, even in the case of several
> > > windows being closed prior to the command that would otherwise be
> > > swallowed.
> > 
> > Ok - thank you both, Pip and Visuwesh for investigating.
> > 
> > Eli, should we install that patch (rather master I guess)?  It fixes the
> > problem for me.
> 
> I think we should install on emacs-30, unless someone can thing of any
> potential problem with it.

No objections, so I've now installed the workaround on the emacs-30
branch, and I'm therefore closing this bug.

Subject: 31.0.50; Calc: g f doesn't display gnuplot window after closing
From: Michael Heerdegen <[email-masked]>
To: [email-masked]
Date: Sat, 24 Aug 2024 07:49:53 +0200
List-Id: <debbugs-submit.debbugs.gnu.org>

Hello,

I'm using a graphical version of Gnuplot in Debian Gnu/Linux.

In Calc, whenever I have displayed a graph view using g f, and then have
been closing the Gnuplot X window, the next g f or g p will always not
display the Gnuplot view.  Hitting the keys again displays it, however.

When I don't close the Gnuplot window, the graph view is updated as
expected.

I found nothing obvious in the Calc code.  In the scenario where the
window doesn't pop up, the Gnuplot process is alive.  I edebugged
`calc-gnuplot-command' and the relevant line

  (process-send-string calc-gnuplot-process cmd)

seems to be the correct call.  When edebugging, simply executing this
very same call makes the Gnuplot window appear!  For some reason,
Gnuplot only displays the window for the second process-send-string
call.  Could be a Gnuplot bug, I dunno.

And...when I redefine `calc-gnuplot-alive' to always fail, the problem
is fixed, in a very inelegant way of course.  So there is something
wrong when talking with Gnuplot, or with Gnuplot itself.

I'm on Debian, I tried several different graphical Gnuplot versions, but
it's the same for all of them.

I'm thankful for all insights.

Michael.