From: Tom Lane <tgl@sss.pgh.pa.us>
To: Tomas Vondra <tomas@vondra.me>
cc: Thomas Munro <thomas.munro@gmail.com>, Andres Freund <andres@anarazel.de>,
        Michael Paquier <michael@paquier.xyz>,
        Andrew Dunstan <andrew@dunslane.net>, Amul Sul <sulamul@gmail.com>,
        Zsolt Parragi <zsolt.parragi@percona.com>,
        Robert Haas <robertmhaas@gmail.com>, Chao Li <li.evan.chao@gmail.com>,
        Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>,
        Fujii Masao <masao.fujii@gmail.com>,
        Jakub Wartak <jakub.wartak@enterprisedb.com>,
        PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: pg_waldump: support decoding of WAL inside tarfile
In-reply-to: <3586483.1775155672@sss.pgh.pa.us>
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Comments: In-reply-to Tom Lane <tgl@sss.pgh.pa.us>
	message dated "Thu, 02 Apr 2026 14:47:52 -0400"
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Date: Thu, 02 Apr 2026 15:15:36 -0400
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I wrote:
> Interestingly, pg_verifybackup's t/003_corruption.pl test also fails
> with the same issue, so apparently this platform is even more
> aggressive about sparse-ifying files than Thomas' FreeBSD box.
> I wonder how come we managed to pass that test case before on
> these machines.

The answer to that seems to be that the test scripts for
pg_verifybackup simply fail to detect when it's mishandling
sparse tar entries.  We only check failing cases not successful
cases, and in each case the error checked for is independent of
whether we would have extracted WAL data correctly.  Grumble.

			regards, tom lane