Re: Leakproofness of texteq()/textne()

Peter Eisentraut <peter(dot)eisentraut(at)2ndquadrant(dot)com> writes:
> On 2019-09-16 06:24, Tom Lane wrote:
>> So it seems that the consensus is that it's okay to mark these
>> functions leakproof, because if any of the errors they throw
>> are truly reachable for other than data-corruption reasons,
>> we would wish to try to prevent such errors. (Maybe through
>> upstream validity checks? Hard to say how we'd do it exactly,
>> when we don't have an idea what the problem is.)

> Yeah, it seems like as we expand our Unicode capabilities, we will see
> more cases like "it could fail here in theory, but it shouldn't happen
> for normal data", and the answer can't be to call all that untrusted or
> leaky. It's the job of the database software to sort that out.
> Obviously, it will require careful evaluation in each case.

Here's a proposed patch to mark functions that depend on varstr_cmp
as leakproof. I think we can apply this to HEAD and then close the
open item as "won't fix for v12".

regards, tom lane