Re: BUG #15595: matchctx->npatterns is always 1 no matter pattern have 0 or 1 subexpression

=?utf-8?q?PG_Bug_reporting_form?= <noreply(at)postgresql(dot)org> writes:
> when I use setup_regexp_matches, I found matchctx->npatterns is always 1 no
> matter pattern have not or one subexpr subexpression.

It seems unlikely that this is a Postgres bug.

Just looking at the code in setup_regexp_matches, I wonder whether you
are passing use_subpatterns = true or not:

/* do we want to remember subpatterns? */
if (use_subpatterns && cpattern->re_nsub > 0)
{
matchctx->npatterns = cpattern->re_nsub;
pmatch_len = cpattern->re_nsub + 1;
}
else
{
use_subpatterns = false;
matchctx->npatterns = 1;
pmatch_len = 1;
}

regards, tom lane