From: Ihor Radchenko <yantar92@gmail.com>
To: Eli Zaretskii <eliz@gnu.org>
Cc: 51766@debbugs.gnu.org, monnier@iro.umontreal.ca
Subject: bug#51766: string-pixel-width limitations (was: bug#51766: 29.0.50; Return value of buffer-chars-modified-tick changes when buffer text is not yet changed before inserting a character for non-latin input methods)
Date: Tue, 21 Jun 2022 21:03:43 +0800 [thread overview]
Message-ID: <874k0eqic0.fsf@localhost> (raw)
In-Reply-To: <83y1xqji8z.fsf@gnu.org>
Note that I changed the topic in this particular branch. My aim here is
to make you aware about the issues with current Emacs tools to measure
pixel-precise string width. Maybe, things can be improved on Emacs side
in this regard.
The below is going back to the initial topic.
Eli Zaretskii <eliz@gnu.org> writes:
> Anyway, the beginning of this sub-thread, specifically about valign,
> was in the context of Lisp programs that do buffer modifications under
> with-silent-modifications or equivalent, and valign seems to do that
> because it just needs to measure the pixel width of a string, and it
> does that by inserting the string and then removing it. So in that
> case, the "buffer modifications" are indeed null and void, and Org
> shouldn't be bothered by such "modifications", because the buffer
> really remains unmodified. Right?
In short, you are right. To clarify the problem on my side goes like:
1. Org has a real issue with bad third-party code inhibiting
before/after-change function + modifications in indirect buffers not
always triggering before/after-change
2. Because the issue is critical and can cause data corruption, we
cannot just ignore it
3. The first attempt to detect "stealthy" modifications was using
buffer-chars-modified-tick
4. But this method is not reliable because (a) quail does some legit
edits under inhibit-modification-hooks; (b) some other code, like
valign also does legit edits under inhibit-modification-hooks
These buffer modifications are harmless from Org perspective.
5. However, We end up with numerous false-positives using (3) and I am
clueless how to reliably detect or work around harmful "stealthy"
edits
- The suggestion to compare buffer size is helpful, but not 100%
reliable
- My other idea to request before/after-change function variants are
too specific to the problem at hand and may be not good for Emacs
in a whole
In any case, bug#51766 should not be considered a bug because quail does
modify the buffer and changes in buffer-chars-modified-tick are legit.
Best,
Ihor
next prev parent reply other threads:[~2022-06-21 13:03 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-11 13:56 bug#51766: 29.0.50; Return value of buffer-chars-modified-tick changes when buffer text is not yet changed before inserting a character for non-latin input methods Ihor Radchenko
2021-11-11 15:19 ` Eli Zaretskii
2021-11-11 15:50 ` Ihor Radchenko
2021-11-11 17:35 ` Eli Zaretskii
2021-11-12 12:06 ` Ihor Radchenko
2021-11-12 12:15 ` Eli Zaretskii
2021-11-12 12:53 ` Ihor Radchenko
2021-11-12 13:09 ` Eli Zaretskii
2021-11-12 13:39 ` Ihor Radchenko
2021-11-12 15:17 ` Eli Zaretskii
2021-11-13 9:10 ` Ihor Radchenko
2021-11-13 10:11 ` Eli Zaretskii
2021-11-13 11:29 ` Ihor Radchenko
2021-11-13 13:38 ` Eli Zaretskii
2021-11-13 14:43 ` Ihor Radchenko
2021-11-13 15:24 ` Eli Zaretskii
2022-06-17 2:54 ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2022-06-17 5:36 ` Eli Zaretskii
2022-06-17 13:16 ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2022-06-17 10:05 ` Ihor Radchenko
2022-06-17 10:50 ` Eli Zaretskii
2022-06-21 4:13 ` bug#51766: string-pixel-width limitations (was: bug#51766: 29.0.50; Return value of buffer-chars-modified-tick changes when buffer text is not yet changed before inserting a character for non-latin input methods) Ihor Radchenko
2022-06-21 10:16 ` Eli Zaretskii
2022-06-21 11:00 ` Ihor Radchenko
2022-06-21 12:17 ` Eli Zaretskii
2022-06-21 12:39 ` Ihor Radchenko
2022-06-21 12:47 ` Eli Zaretskii
2022-06-21 13:03 ` Ihor Radchenko [this message]
2022-06-22 23:49 ` bug#51766: string-pixel-width limitations Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2022-06-17 13:28 ` bug#51766: 29.0.50; Return value of buffer-chars-modified-tick changes when buffer text is not yet changed before inserting a character for non-latin input methods Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2022-06-21 4:14 ` Ihor Radchenko
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