postgres/contrib/test_decoding/sql
Tom Lane bfb69b1e5d Fix crash when logical decoding is invoked from a PL function.
The logical decoding functions do BeginInternalSubTransaction and
RollbackAndReleaseCurrentSubTransaction to clean up after themselves.
It turns out that AtEOSubXact_SPI has an unrecognized assumption that
we always need to cancel the active SPI operation in the SPI context
that surrounds the subtransaction (if there is one).  That's true
when the RollbackAndReleaseCurrentSubTransaction call is coming from
the SPI-using function itself, but not when it's happening inside
some unrelated function invoked by a SPI query.  In practice the
affected callers are the various PLs.

To fix, record the current subtransaction ID when we begin a SPI
operation, and clean up only if that ID is the subtransaction being
canceled.

Also, remove AtEOSubXact_SPI's assertion that it must have cleaned
up the surrounding SPI context's active tuptable.  That's proven
wrong by the same test case.

Also clarify (or, if you prefer, reinterpret) the calling conventions
for _SPI_begin_call and _SPI_end_call.  The memory context cleanup
in the latter means that these have always had the flavor of a matched
resource-management pair, but they weren't documented that way before.

Per report from Ben Chobot.

Back-patch to 9.4 where logical decoding came in.  In principle,
the SPI changes should go all the way back, since the problem dates
back to commit 7ec1c5a86.  But given the lack of field complaints
it seems few people are using internal subtransactions in this way.
So I don't feel a need to take any risks in 9.2/9.3.

Discussion: https://postgr.es/m/73FBA179-C68C-4540-9473-71E865408B15@silentmedia.com
2017-10-06 19:18:59 -04:00
..
binary.sql test_decoding: Protect against rare spurious test failures. 2015-09-22 15:47:53 +02:00
ddl.sql Fix core dump in ReorderBufferRestoreChange on alignment-picky platforms. 2016-04-14 19:42:22 -04:00
decoding_in_xact.sql Add skip-empty-xacts option to test_decoding for use in the regression tests. 2014-09-01 16:08:57 +02:00
decoding_into_rel.sql Fix crash when logical decoding is invoked from a PL function. 2017-10-06 19:18:59 -04:00
permissions.sql Add skip-empty-xacts option to test_decoding for use in the regression tests. 2014-09-01 16:08:57 +02:00
prepared.sql Add skip-empty-xacts option to test_decoding for use in the regression tests. 2014-09-01 16:08:57 +02:00
rewrite.sql Add skip-empty-xacts option to test_decoding for use in the regression tests. 2014-09-01 16:08:57 +02:00
spill.sql Make contrib/test_decoding regression tests safe for CZ locale. 2016-11-21 20:39:28 -05:00
toast.sql Fix issues with wide tuples being updated and REPLICA IDENTITY FULL. 2017-08-05 14:56:40 -07:00
xact.sql Don't propagate a null subtransaction snapshot up to parent transaction. 2016-08-07 13:15:55 -04:00