Обсуждение: [COMMITTERS] pgsql: Handle OID column inheritance correctly in ALTER TABLE ...INHER

Handle OID column inheritance correctly in ALTER TABLE ... INHERIT.

Inheritance operations must treat the OID column, if any, much like
regular user columns.  But MergeAttributesIntoExisting() neglected to
do that, leading to weird results after a table with OIDs is associated
to a parent with OIDs via ALTER TABLE ... INHERIT.

Report and patch by Amit Langote, reviewed by Ashutosh Bapat, some
adjustments by me.  It's been broken all along, so back-patch to
all supported branches.

Discussion: https://postgr.es/m/cb13cfe7-a48c-5720-c383-bb843ab28298@lab.ntt.co.jp

Branch
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REL9_4_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/696d40d303af1e92fbbe4192a93c5a94340fc22c

Modified Files
--------------
src/backend/commands/tablecmds.c      | 33 +++++++++++++++++++++++
src/test/regress/expected/inherit.out | 49 +++++++++++++++++++++++++++++++++++
src/test/regress/sql/inherit.sql      | 26 +++++++++++++++++++
3 files changed, 108 insertions(+)