pgsql: Fix bug with view locking code.

Fix bug with view locking code.

LockViewRecurese() obtains view relation using heap_open() and passes
it to get_view_query() to get view info. It immediately closes the
relation then uses the returned view info by calling
LockViewRecurse_walker().  Since get_view_query() returns a pointer
within the relcache, the relcache should be kept until
LockViewRecurse_walker() returns. Otherwise the relation could point
to a garbage memory area.

Fix is moving the heap_close() call after LockViewRecurse_walker().

Problem reported by Tom Lane (buildfarm is unhappy, especially prion
since it enables -DRELCACHE_FORCE_RELEASE cpp flag), fix by me.

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/1b26bd4089a388929c644ffea2832f3841c25969

Modified Files
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src/backend/commands/lockcmds.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)