Laurenz Albe <laurenz.albe@cybertec.at> writes:
> On Wed, 2023-11-08 at 11:58 +0000, Dean Rasheed wrote:
>> This should overflow, since the correct result (+9223372036854775808)
>> is out of range. However, on platforms without integer overflow
>> builtins or 128-bit integers, pg_sub_s64_overflow() does the
>> following:
>> ...
>> which fails to spot the fact that overflow is also possible when a ==
>> 0. So on such platforms, it returns the wrong result.
>>
>> Patch attached.
> The patch looks good to me.
+1: good catch, fix looks correct.
regards, tom lane