Re: Internal error with gawk-5.3.0

[Miguel Pineiro Jr.]

I can replicate the core dump of the program in the original report, but 
simplified it to:

LC_CTYPE=en_US.UTF-8 ./gawk 'BEGIN { print match (m, /a?/) }'

LC_CTYPE=C works fine. And in a multibyte locale it also works if the 
uinitialized m is replaced with an empty string literal.

This is very likely related to changes made a few months ago to fix zero-length 
matches in multibyte locales: 
https://git.savannah.gnu.org/cgit/gawk.git/commit/?id=c85749daba596ba2b827bcea239db74fc5321665

I'm going to take a look at it right now, to see if I can help get this fixed 
quickly.

Miguel