Improve behavior of concurrent rename statements.

Previously, renaming a table, sequence, view, index, foreign table,
column, or trigger checked permissions before locking the object, which
meant that if permissions were revoked during the lock wait, we would
still allow the operation.  Similarly, if the original object is dropped
and a new one with the same name is created, the operation will be allowed
if we had permissions on the old object; the permissions on the new
object don't matter.  All this is now fixed.

Along the way, attempting to rename a trigger on a foreign table now gives
the same error message as trying to create one there in the first place
(i.e. that it's not a table or view) rather than simply stating that no
trigger by that name exists.

Patch by me; review by Noah Misch.

1 files changed, 2 insertions, 6 deletions

diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c
index edec44d2c3d..e805e28a39e 100644
--- a/src/backend/commands/cluster.c
+++ b/src/backend/commands/cluster.c
@@ -1474,28 +1474,24 @@ finish_heap_swap(Oid OIDOldHeap, Oid OIDNewHeap,
 		{
 			Relation	toastrel;
 			Oid			toastidx;
-			Oid			toastnamespace;
 			char		NewToastName[NAMEDATALEN];
 
 			toastrel = relation_open(newrel->rd_rel->reltoastrelid,
 									 AccessShareLock);
 			toastidx = toastrel->rd_rel->reltoastidxid;
-			toastnamespace = toastrel->rd_rel->relnamespace;
 			relation_close(toastrel, AccessShareLock);
 
 			/* rename the toast table ... */
 			snprintf(NewToastName, NAMEDATALEN, "pg_toast_%u",
 					 OIDOldHeap);
 			RenameRelationInternal(newrel->rd_rel->reltoastrelid,
-								   NewToastName,
-								   toastnamespace);
+								   NewToastName);
 
 			/* ... and its index too */
 			snprintf(NewToastName, NAMEDATALEN, "pg_toast_%u_index",
 					 OIDOldHeap);
 			RenameRelationInternal(toastidx,
-								   NewToastName,
-								   toastnamespace);
+								   NewToastName);
 		}
 		relation_close(newrel, NoLock);
 	}