The first patch tries to close every Perl-to-SQL path that still
ignored FETCH on tied values.
I have attached v2.
The previous version missed a few GETMAGIC call sites:
get_perl_array_ref(), the trigger return value, $_TD->{new} before
the SvOK() / SvROK() checks, and the start of return_next(). A tied
scalar whose FETCH returns an arrayref or a hashref still looked like
undef.
That also made the SETOF walker cleaner. The loop only walks with
av_len() and calls return_next(). FETCH lives in return_next() and
plperl_sv_to_datum(), so the loop does not run GETMAGIC on each
element itself.
The regress patch covers those cases. tied_scalar_setof and
tied_scalar_int_array wrap an arrayref in a tied scalar. tied_modify
uses tied scalars for $_TD->{new} and for the "MODIFY" return.
