Protect against malformed timestamps. Also protect against negative WalSegSz
as it triggers division by zero:
((0x100000000UL) / (WalSegSz)) can turn into zero in
XLogFileName(xlogfilename, ControlFile->checkPointCopy.ThisTimeLineID,
segno, WalSegSz);
because if WalSegSz is -1 then by arithmetic rules in C we get
0x100000000UL / 0xFFFFFFFFFFFFFFFFUL == 0.
Author: Ilyasov Ian <ianilyasov@outlook.com>
Author: Anton Voloshin <a.voloshin@postgrespro.ru>
Backpatch-through: 13
d54d5668b4