Re: inappropriate use of nroff-mode leads to grief

["Stefan Monnier <foo@acm.com>" <monnier+gnu.emacs.help/news/@flint.cs.yale.edu>]

>>>>> "Robert" == Robert Marshall <spam@capuchin.co.uk> writes:
> I use logrotate to compress /var/log files so these are saved as (e.g)
> syslog.1.gz

That's unfortunate.  We should try to provide a fix for it.

>   parse-partial-sexp(1 9649428)

Aaarrg!!
nroff-mode tries to avoid such large scans by setting
font-lock-beginning-of-defun to something more-or-less meaningful
(beginning-of-paragraph, IIRC) but in your case that doesn't help
because there's probably no empty line so it still ends up
scanning everything.

The development version of Emacs improves this by caching the result
of the scan, so it does large scans as well, but hopefully not too often.
(i.e. the first time you jump to the end of the file, it will scan the
whole file, but after wards it will only rescan smaller parts of it).


        Stefan