Re: pg_veryfybackup can fail with a valid backup for TLI > 1

On Fri, Aug 20, 2021 at 04:47:15PM +0900, Kyotaro Horiguchi wrote:
> Yes, backup_label looks correct.
>
> backup_label (extract):
> START WAL LOCATION: 0/5000028 (file 000000020000000000000005)
> CHECKPOINT LOCATION: 0/5000060
> START TIMELINE: 2

Okay.  I have worked on that today, did more manual tests, and applied
this fix down to 13.  The cherry-pick from 14 to 13 only required a
s/$master/$primary/ in the test, which was straight-forward.  Your
patch for 13 did that though:
-                       if (starttli != entry->tli)
+                       if (!XLogRecPtrIsInvalid(entry->begin))

So it would have caused a failure with parent TLIs that have a correct
begin location, but we expect the opposite.  The patch for 14/HEAD had
that right.
--
Michael