Re: BUG #17847: Unaligned memory access in ltree_gist

On Tue, 18 Apr 2023 at 15:11, Pavel Borisov <pashkin(dot)elfe(at)gmail(dot)com> wrote:
>
> Hi, Alexander!
>
> On Tue, 18 Apr 2023 at 14:57, Alexander Korotkov <aekorotkov(at)gmail(dot)com> wrote:
> >
> > Hi, Pavel!
> >
> > On Tue, Apr 18, 2023 at 1:34 PM Pavel Borisov <pashkin(dot)elfe(at)gmail(dot)com> wrote:
> > > I've looked into the patch v2 and there is a difference in DETAIL text
> > > for the cases:
> > >
> > > (1)
> > > create index tstidx on ltreetest using gist (t gist_ltree_ops(siglen=2025));
> > > +ERROR: siglen value must be integer-aligned
> > > +DETAIL: Valid values are int-aligned positive integers up to 2024.
> > >
> > > (2)
> > > +create index tstidx on ltreetest using gist (t gist_ltree_ops(siglen=2028));
> > > +ERROR: value 2028 out of bounds for option "siglen"
> > > +DETAIL: Valid values are between "4" and "2024"
> > >
> > > Could we stick to the DETAIL like in (2) for both cases?
> >
> > Within ltree we don't have control over error messages, which GUC code
> > emits about min/max boundaries violation (for sure, we're not going to
> > patch GUC code in this fix). So the only thing I can do to match
> > these two DETAIL is to make both of them 'Valid values are between "4"
> > and "2024"'. However, this message would be kind of irrelevant for
> > "siglen value must be integer-aligned" error. It's strange for me
> > when an error mentions alignment, but DETAIL does not.
> >
> > Do you think we can just remove the DETAIL for "siglen value must be
> > integer-aligned" error?
>
> I'd just propose something like making DETAIL output in ltree look
> similar to GUC validation (patch v3). But it's minor and could be done
> by removing DETAIL at all or otherwise.
I think my confusion on error output is due to alignment being checked
first, then limits. So in DETAIL I see different error reasons for
2025 and 2028.

Pavel