Re: Odd 9.4, 9.3 buildfarm failure on s390x

Andres Freund <andres(at)anarazel(dot)de> writes:
> On 2018-10-01 12:13:57 -0400, Tom Lane wrote:
>> Yeah. So our choices are
>>
>> (1) Retain the current restriction on what sort comparators can
>> produce. Find all the places where memcmp's result is returned
>> directly, and fix them. (I wonder if strcmp has same issue.)
>>
>> (2) Drop the restriction. This'd require at least changing the
>> DESC correction, and maybe other things. I'm not sure what the
>> odds would be of finding everyplace we need to check.
>>
>> Neither one is sounding very pleasant, or maintainable.

> (2) seems more maintainable to me (or perhaps less unmaintainable). It's
> infrastructure, rather than every datatype + support out there...

I guess we could set up some testing infrastructure: hack int4cmp
and/or a couple other popular comparators so that they *always*
return INT_MIN, 0, or INT_MAX, and then see what falls over.

I'm fairly sure that btree, as well as the sort code proper,
has got an issue here.

regards, tom lane