Re: Fix overflow in DecodeInterval

I wrote:
> Joseph Koshakow <koshy44@gmail.com> writes:
>> I think I know that the issue is. It's with `ParseISO8601Number` and
>> the minutes field "1.".
>> Previously that function parsed the entire field into a single double,
>> so "1." would
>> be parsed into 1.0. Now we try to parse the integer and decimal parts
>> separately. So
>> we first parse "1" into 1 and then fail to "." into anything because
>> it's not a valid decimal.

> Interesting point, but then why doesn't it fail everywhere?

Oh ... a bit of testing says that strtod() on an empty string
succeeds (returning zero) on Linux, but fails with EINVAL on
AIX.  The latter is a lot less surprising than the former,
so we'd better cope.

(Reading POSIX with an eagle eye, it looks like both behaviors
are allowed per spec: this is why you have to check that endptr
was advanced to be sure everything is kosher.)

            regards, tom lane