From: Tom Lane <tgl@sss.pgh.pa.us>
To: Fabien COELHO <coelho@cri.ensmp.fr>
cc: Peter Eisentraut <peter.eisentraut@enterprisedb.com>,
        Michael Paquier <michael@paquier.xyz>,
        Julien Rouhaud <rjuju123@gmail.com>,
        "shiy.fnst@fujitsu.com" <shiy.fnst@fujitsu.com>,
        "pgsql-hackers@lists.postgresql.org"
 <pgsql-hackers@lists.postgresql.org>
Subject: Re: psql - add SHOW_ALL_RESULTS option
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Comments: In-reply-to Fabien COELHO <coelho@cri.ensmp.fr>
	message dated "Fri, 09 Apr 2021 20:04:11 +0200"
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Date: Sun, 11 Apr 2021 11:14:07 -0400
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 <https://www.postgresql.org/message-id/2671235.1618154047%40sss.pgh.pa.us>
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Coverity has pointed out another problem with this patch:

/srv/coverity/git/pgsql-git/postgresql/src/bin/psql/common.c: 1425 in Send=
Query()
1419     				/*
1420     				 * Do nothing if they are messing with savepoints themselves:
1421     				 * If the user did COMMIT AND CHAIN, RELEASE or ROLLBACK, our
1422     				 * savepoint is gone. If they issued a SAVEPOINT, releasing
1423     				 * ours would remove theirs.
1424     				 */
>>>     CID 1476042:  Control flow issues  (DEADCODE)
>>>     Execution cannot reach the expression "strcmp(PQcmdStatus(results)=
, "COMMIT") =3D=3D 0" inside this statement: "if (results && (strcmp(PQcm.=
..".
1425     				if (results &&
1426     					(strcmp(PQcmdStatus(results), "COMMIT") =3D=3D 0 ||
1427     					 strcmp(PQcmdStatus(results), "SAVEPOINT") =3D=3D 0 ||
1428     					 strcmp(PQcmdStatus(results), "RELEASE") =3D=3D 0 ||
1429     					 strcmp(PQcmdStatus(results), "ROLLBACK") =3D=3D 0))
1430     					svptcmd =3D NULL;

It's right: this is dead code because all paths through the if-nest
starting at line 1373 now leave results =3D NULL.  Hence, this patch
has broken the autocommit logic; it's no longer possible to tell
whether we should do anything with our savepoint.

Between this and the known breakage of control-C, it seems clear
to me that this patch was nowhere near ready for prime time.
I think shoving it in on the last day before feature freeze was
ill-advised, and it ought to be reverted.  We can try again later.

			regards, tom lane