Re: perl: unsafe empty pattern behavior

Jeff Davis <pgsql@j-davis.com> writes:
> On Tue, 2024-03-12 at 18:53 +0100, Alvaro Herrera wrote:
>> I also tried grepping (for things
>> like qr{}, qr[], qr||, qr!!) and didn't find anything beyond what you
>> have ... but I only looked for the "qr" literal, not other ways to
>> get regexes.

> I think that's fine. qr// seems the most dangerous, because it seems to
> behave differently in different versions of perl.

I wonder whether perlcritic has sufficiently deep understanding of
Perl code that it could find these hazards.  I already checked,
and found that there's no built-in filter for this (at least not
in the perlcritic version I have), but maybe we could write one?
The rules seem to be plug-in modules, so you can make your own
in principle.

            regards, tom lane