Re: Residual cleanups for tied objects in PL/Perl

вс, 16 авг. 2026 г. в 22:38, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>:One interesting
point is that Claude Opus, which constructed

> these test cases, seemed to think that we ought to be able
> to read out the values assigned to the tied array or hash.
> But what the repaired code actually produces is SQL NULLs.
> AFAICT we are getting Perl "undef" values out of hv_iternext
> or av_fetch, so it's hard to see how we could do any better.
>
> Hi Tom!

A tied hash does not store the value in HeVAL(). hv_iternext() leaves that
pointer unset. Tom's NULL check therefore always takes the SQL NULL path,
even when FETCH would return a real value. hv_iterval() plus SvGETMAGIC()
is what actually runs FETCH.

The same applies to a tied array. av_len() stops the infinite loop, but
av_fetch() still returns a magic SV whose SvOK() is false until GETMAGIC.
Without that, SETOF also yields NULLs.

The attached patch includes regress tests. They use a small inline TIEHASH
/ TIEARRAY class, not Tie::Hash or Tie::Array.

--
Regards,
Rachitskiy Andrey