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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master

Details
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http://git.postgresql.org/pg/commitdiff/e31d524867130d3c54b8d5f4c5ed59e2fcd07867

Modified Files
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src/backend/catalog/dependency.c | 44 +++++++++++++++++++-------------------
1 files changed, 22 insertions(+), 22 deletions(-)