Re: BUG #17066: Cache lookup failed when null (unknown) is passed as anycompatiblemultirange

On Wed, Jun 23, 2021 at 6:31 PM Alexander Korotkov <aekorotkov@gmail.com> wrote:
> On Tue, Jun 22, 2021 at 7:01 PM Alexander Korotkov <aekorotkov@gmail.com> wrote:
> > On Tue, Jun 22, 2021 at 4:42 PM Alvaro Herrera <alvherre@2ndquadrant.com> wrote:
> > > On 2021-Jun-22, Neil Chen wrote:
> > >
> > > > Greetings,
> > > >
> > > > I tried to investigate the bug, but the complicated logic here completely
> > > > messed up my mind...
> > > >
> > > > Anyway, this patch can fix it and make the regress test happy. But I think
> > > > it's better to get the author's advice - I copied this email to Alvaro,
> > > > hope it doesn't offend him...
> > >
> > > Without looking too deeply, the patch seems sensible to me.  However,
> > > I'm CC'ing Alexander and Paul :-)
> >
> > Thank you for pointing this out.  And thanks to Neil for the fix.
> >
> > Looks good at the first glance.  I'm going to review this in the next
> > couple of days.
>
> I've reviewed enforce_generic_type_consistency() more carefully.  It
> looks for me that this function requires more significant rework.  For
> instance, these two functions throw errors, but it seems that both of
> them should work.
>
> create function multirange_func(r anycompatiblerange)
>   returns anycompatiblemultirange as 'select multirange($1);' language sql;
> create function range_func(r anycompatiblemultirange)
>   returns anycompatiblerange as 'select multirange($1);' language sql;
>
> # select multirange_func(int4range(1,10));
> ERROR:  could not identify anycompatiblemultirange type
>
> # select range_func(int4multirange(int4range(1,10)));
> ERROR:  could not determine polymorphic type anycompatiblerange
> because input has type unknown
>
> So, I'm still investigating this.

The second function was intended to be this to be a meaningful
example.  But anyway it fails with the same error.

create function range_func(r anycompatiblemultirange)
  returns anycompatiblerange as 'select range_merge($1);' language sql;

------
Regards,
Alexander Korotkov