bug#25682: 25.1; font-lock: fontifying too slow in some modes on very long lines

[Lars Ingebrigtsen]

Ryan B <public@ryanb.org> writes:

> i occasionally have very long lines in some buffers, e.g. 10k-20k characters.
> font-lock-mode often hangs for a long time (5-10s) when fontifying these 
> lines.

These issues have been fixed in Emacs 29 -- long lines no longer slows
down Emacs (to these degrees), so I'm closing this bug report.  (And I'm
not able to reproduce the problem in the test case here with the current
Emacs.)

There may be issues remaining with long lines, and if so, please open
new bug reports for those issues (and cases for reproduction would be
appreciated).