From: Eli Zaretskii <eliz@gnu.org>
To: geza.herman@gmail.com
Cc: Gregory Heytings <gregory@heytings.org>, 66764@debbugs.gnu.org
Subject: bug#66764: 29.1; Emacs scrolls for "(goto-char (point-max))" instead of jumping
Date: Fri, 27 Oct 2023 09:50:33 +0300 [thread overview]
Message-ID: <831qdgftja.fsf@gnu.org> (raw)
In-Reply-To: <83a5s4fwih.fsf@gnu.org> (message from Eli Zaretskii on Fri, 27 Oct 2023 08:46:14 +0300)
OK, I think I see the root cause of the problem: it's your
font-lock-keywords setting, viz.:
(font-lock-add-keywords nil '(((lambda (bound)) (1 'error prepend t))) t)
Without this setting, everything works as expected, and goto-char goes
to the EOB almost instantaneously, even when scroll-conservatively is
set to a large value.
AFAIU, the font-lock-keywords setting above causes the display engine
to call this function every time it moves across some chunk of text,
which slows down redisplay. This shows with scroll-conservatively set
to a large value because Emacs then attempts to find the minimum
amount of scrolling the screen in order to bring point into the view.
It is a known fact that modes which use advanced font-lock settings
should adapt to the long-line situation (when the function
long-line-optimizations-p returns non-nil), so I think you should
modify your font-lock settings to avoid this problem in that case.
CC'ing Gregory in case I missed something in this scenario.
next prev parent reply other threads:[~2023-10-27 6:50 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-26 17:04 bug#66764: 29.1; Emacs scrolls for "(goto-char (point-max))" instead of jumping Geza Herman
2023-10-26 18:25 ` Eli Zaretskii
2023-10-26 19:12 ` Herman, Géza
2023-10-27 5:46 ` Eli Zaretskii
2023-10-27 6:50 ` Eli Zaretskii [this message]
2023-10-27 9:43 ` Herman, Géza
2023-11-04 8:29 ` Eli Zaretskii
2023-11-18 9:01 ` Eli Zaretskii
2023-11-25 11:37 ` Gregory Heytings
2023-12-09 13:33 ` Eli Zaretskii
2023-12-23 8:37 ` Eli Zaretskii
2023-12-28 10:53 ` Gregory Heytings
2024-01-09 20:01 ` Eli Zaretskii
2024-01-11 23:40 ` Gregory Heytings
2024-01-13 19:11 ` Eli Zaretskii
2024-01-14 19:36 ` Eli Zaretskii
2024-01-14 22:06 ` Gregory Heytings
2024-01-15 12:22 ` Eli Zaretskii
2024-01-15 13:30 ` Gregory Heytings
2024-01-13 19:10 ` Eli Zaretskii
2024-01-13 19:13 ` Eli Zaretskii
2023-10-27 9:22 ` Herman, Géza
2023-10-27 10:43 ` Eli Zaretskii
2023-10-28 1:15 ` Geza Herman
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