pgsql: Fix intermittent crash in DROP INDEX CONCURRENTLY.

Fix intermittent crash in DROP INDEX CONCURRENTLY.

When deleteOneObject closes and reopens the pg_depend relation,
we must see to it that the relcache pointer held by the calling function
(typically performMultipleDeletions) is updated. Usually the relcache
entry is retained so that the pointer value doesn't change, which is why
the problem had escaped notice ... but after a cache flush event there's
no guarantee that the same memory will be reassigned. To fix, change
the recursive functions' APIs so that we pass around a "Relation *"
not just "Relation".

Per investigation of occasional buildfarm failures. This is trivial
to reproduce with -DCLOBBER_CACHE_ALWAYS, which points up the sad
lack of any buildfarm member running that way on a regular basis.

Branch
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REL9_2_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/4863ed8f372f2d38f1870fb668b8a99097223cf7

Modified Files
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src/backend/catalog/dependency.c | 36 ++++++++++++++++++------------------
1 files changed, 18 insertions(+), 18 deletions(-)