From: Gerry Agbobada <gagbobada@gmail.com>
To: Eli Zaretskii <eliz@gnu.org>
Cc: Emacs developers <emacs-devel@gnu.org>
Subject: Re: Question about composite.c
Date: Sat, 25 Apr 2020 15:53:49 +0200 [thread overview]
Message-ID: <CAHhDRB_nG8PrYTjX0ehF_EVHOLiq534Y8JFGoArftcdSSon5DQ@mail.gmail.com> (raw)
In-Reply-To: <CAHhDRB9ssNpuRbU8ttiVRRw0GGuU84oiG7qKqRMeSzpEceVchQ@mail.gmail.com>
I can confirm the bug is fixed by
commit fe903c5ab7354b97f80ecf1b01ca3ff1027be446
Author: Eli Zaretskii
Date: Sat Feb 8 15:41:36 2020 +0200
Allow composition of pure-ASCII strings in the mode line
* src/composite.c (Fcomposition_get_gstring): Allow unibyte strings if
they are pure
ASCII, by copying text into a multibyte string.
If it's possible to backport this commit in emacs 27 I think it would
save a lot of headaches.
I still don't know what exactly I did wrong with that combination of
overlays and ligatures,
but since it's fixed in master I won't look a lot more into that ; I
will just try to understand what
this patch does.
Best regards,
Gerry AGBOBADA
Le sam. 25 avr. 2020 à 15:29, Gerry Agbobada <gagbobada@gmail.com> a écrit :
>
> I cannot reproduce the bug even with my complex example on master, but
> still can reproduce it on 05089a4d (tip of emacs-27 last week).
>
> Bissecting will take a while but I'll try to find what commit changed
> the behaviour so I can understand a bit more.
>
> Gerry AGBOBADA
>
> Le sam. 25 avr. 2020 à 15:06, Gerry Agbobada <gagbobada@gmail.com> a écrit :
> >
> > > Is the overlay a necessary part of the problem?
> > Yes, because it's the overlay that tries to print a composed "=>" combination.
> >
> >
> > > Also, is it necessaryto define a separate char-table, instead of using
> > > composition-function-table?
> > > The example looks quite complex, and I wonder whether you could
> > > prepare a simplified variant that only included the parts that are
> > > necessary? That would make debugging this issue much easier.
> > I agree that it might still be a little complex. I'll try to work on
> > this again to provide
> > the minimum amount of basic elisp functions code, but it's a little hard for me
> > to pindown the exact issue so I'm just making baby steps for the moment.
> >
> > > From this, I don't think I understand why the problem is triggered by
> > > a '+' character. If I do the following in "emacs -Q":
> > The problem is not triggered by the '+' character but by eros-mode
> > which will try to
> > output an overlay on the cursor with the content "=> 5".
> >
> > > In what version of Emacs do you see these infloops, btw?
> > I was at e1f0e0892 (tip of emacs-27 on Wed Mar 25 21:54:21 2020 +0200 )
> > I will build from master right now to continue the investigation.
> >
> > Thanks for your time answering me
> >
> > Gerry AGBOBADA
> >
> > Le sam. 25 avr. 2020 à 14:44, Eli Zaretskii <eliz@gnu.org> a écrit :
> > >
> > > > From: Gerry Agbobada <gagbobada@gmail.com>
> > > > Date: Wed, 15 Apr 2020 00:43:59 +0200
> > > > Cc: emacs-devel@gnu.org
> > > >
> > > > It took me a good while, but I found a case where :
> > > > - I can reproduce with =emacs -q= (Reproducing infinite looping in
> > > > composition_get_gstring with an empty non-nil string)
> > > > - prettify-symbols-mode is not enabled
> > > >
> > > > The example includes the code of eros.el package, which creates an
> > > > overlay when calling eval-last-sexp. The overlay is supposed to start
> > > > with `=>`, and when I have this in my composition-function-table it
> > > > triggers the loop.
> > > > As explained in the file linked below, with the cursor on `(+ 3 2)|`
> > > > I'd expect `C-x C-e` to create an overlay with `=> 5`. Instead, it
> > > > loops indefinitely and the only way out is to kill -9 emacs (kill
> > > > -USR2 doesn't help)
> > >
> > > Is the overlay a necessary part of the problem? Also, is it necessary
> > > to define a separate char-table, instead of using
> > > composition-function-table?
> > >
> > > The example looks quite complex, and I wonder whether you could
> > > prepare a simplified variant that only included the parts that are
> > > necessary? That would make debugging this issue much easier.
> > >
> > > > (let ((alist
> > > > '(
> > > > (?= . "=>") ; Matches =>
> > > > )))
> > > > (dolist (char-regexp alist)
> > > > (set-char-table-range other-composition-ligature-table (car char-regexp)
> > > > `([,(cdr char-regexp) 0 font-shape-gstring]))))
> > > >
> > > > (set-char-table-parent other-composition-ligature-table composition-function-table)
> > > >
> > > > (setq-local composition-function-table other-composition-ligature-table)
> > >
> > > From this, I don't think I understand why the problem is triggered by
> > > a '+' character. If I do the following in "emacs -Q":
> > >
> > > (set-char-table-range composition-function-table
> > > #x3d
> > > (list (vector "=>" 0 'compose-gstring-for-graphic)))
> > >
> > > and then type (+ 2 3)C-x C-e, I don't get any loop, and no characters
> > > related to the => ligatures anywhere. What am I missing?
> > >
> > > In what version of Emacs do you see these infloops, btw?
next prev parent reply other threads:[~2020-04-25 13:53 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-20 22:17 Question about composite.c Gerry Agbobada
2020-01-21 18:15 ` Eli Zaretskii
2020-01-21 18:57 ` Gerry Agbobada
2020-01-21 19:15 ` Eli Zaretskii
2020-01-22 8:55 ` Gerry Agbobada
2020-04-14 22:43 ` Gerry Agbobada
2020-04-15 1:10 ` Noam Postavsky
2020-04-15 7:39 ` Gerry Agbobada
2020-04-25 12:44 ` Eli Zaretskii
2020-04-25 13:06 ` Gerry Agbobada
2020-04-25 13:29 ` Gerry Agbobada
2020-04-25 13:53 ` Gerry Agbobada [this message]
2020-04-25 15:23 ` Eli Zaretskii
2020-04-25 15:32 ` Gerry Agbobada
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