Fix overflow check in tm2timestamp (this time for sure).

Tom Lane <tgl@sss.pgh.pa.us>

Commit: da5f032a8350a77aeed4f9d459633055f0adb645
Author: Tom Lane <tgl@sss.pgh.pa.us>
Date: 2013-03-04T20:14:13Z
Releases: 9.0.13
Fix overflow check in tm2timestamp (this time for sure).

I fixed this code back in commit 841b4a2d5, but didn't think carefully
enough about the behavior near zero, which meant it improperly rejected
1999-12-31 24:00:00.  Per report from Magnus Hagander.

Files