bug#46889: cperl-mode: Fix indentation issues [PATCH]

[Harald Jörg]

haj@posteo.de (Harald Jörg) writes:

> Hello Emacs-Maintainers,
>
> this started out as working on Bug#42169 but it soon became clear that
> there's more lurking in CPerl mode's indentation code, so I decided to
> open a new issue here.
>
> In 7b2448ae (cperl-mode: Improve detection of index entries for imenu),
> committed on Feb 17, the imenu part of Bug#42169 has been fixed.  This
> commit now fixes the indentation after a package which brings its own
> block.
>
> Therefore, the patch in this report should finally fix Bug#42169.
>
> As a by-catch, the new code fixes the ancient Bug#8077.
>
> This patch also fixes the first part of Bug#11733.  The "other
> indentation bug" reported in Bug#11733 (using a colon as a Perl regexp
> terminator) is a different story and not covered by this patch.
>
> Also fixed now (without known bug number): labels with a space before,
> or a comment after the colon are now correctly indented and fontified.
>
> With this patch in effect, CPerl mode should finally have caught up with
> Perl 5.30!
>
> Many thanks to Mattias Engdegård for his patient explanations how rx
> expressions can be used without breaking compatibility to Emacs 26.1.
> Until now, this allowed two ugly regexp literals to be eliminated.