Re: pgsql: Move tar detection and compression logic to common.

On Wed, Jul 22, 2026 at 12:23 PM Robert Haas <robertmhaas(at)gmail(dot)com> wrote:

> On Fri, Mar 20, 2026 at 3:32 PM Andrew Dunstan <andrew(at)dunslane(dot)net>
> wrote:
> > Move tar detection and compression logic to common.
> >
> > Consolidate tar archive identification and compression-type detection
> > logic into a shared location. Currently used by pg_basebackup and
> > pg_verifybackup, this functionality is also required for upcoming
> > pg_waldump enhancements.
> >
> >
> https://git.postgresql.org/pg/commitdiff/c8a350a439826267186c187dbfbf1f839f7521aa
>
> Unfortunately, this commit not only consolidated the logic but also
> changed the behavior at both of the then-existing call sites for the
> worse.
>
> I attach a patch to undo those behavior changes, which I intend to
> commit and back-patch to v19.
>
>

Thanks, Robert. The change in precheck_tar_backup could possibly do with a
comment like "Make sure there's nothing between the expected prefix and
suffix". I had to look hard to see what it was doing.

cheers

andrew