pgsql: Fix small query-lifespan memory leak in bulk updates.

Fix small query-lifespan memory leak in bulk updates.

When there is an identifiable REPLICA IDENTITY index on the target table,
heap_update leaks the id_attrs bitmapset. That's not many bytes, but it
adds up over enough rows, since the code typically runs in a query-lifespan
context. Bug introduced in commit e55704d8b, which did a rather poor job
of cloning the existing use-pattern for RelationGetIndexAttrBitmap().

Per bug #14293 from Zhou Digoal. Back-patch to 9.4 where the bug was
introduced.

Report: <20160824114320(dot)15676(dot)45171(at)wrigleys(dot)postgresql(dot)org>

Branch
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REL9_4_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/566afa15c8dc64430dfb1e95c661e5875863253c

Modified Files
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src/backend/access/heap/heapam.c | 2 ++
1 file changed, 2 insertions(+)