1 files changed, 51 insertions, 12 deletions

diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c
index b205deca29f..f4c93e5b254 100644
--- a/src/backend/commands/trigger.c
+++ b/src/backend/commands/trigger.c
@@ -1152,6 +1152,39 @@ get_trigger_oid(Oid relid, const char *trigname, bool missing_ok)
 }
 
 /*
+ * Perform permissions and integrity checks before acquiring a relation lock.
+ */
+static void
+RangeVarCallbackForRenameTrigger(const RangeVar *rv, Oid relid, Oid oldrelid,
+								 void *arg)
+{
+    HeapTuple       tuple;
+    Form_pg_class   form;
+
+	tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
+	if (!HeapTupleIsValid(tuple))
+		return;                         /* concurrently dropped */
+	form = (Form_pg_class) GETSTRUCT(tuple);
+
+	/* only tables and views can have triggers */
+    if (form->relkind != RELKIND_RELATION && form->relkind != RELKIND_VIEW)
+        ereport(ERROR,
+                (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+                 errmsg("\"%s\" is not a table or view", rv->relname)));
+
+	/* you must own the table to rename one of its triggers */
+    if (!pg_class_ownercheck(relid, GetUserId()))
+        aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS, rv->relname);
+    if (!allowSystemTableMods && IsSystemClass(form))
+        ereport(ERROR,
+                (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+                 errmsg("permission denied: \"%s\" is a system catalog",
+						rv->relname)));
+
+	ReleaseSysCache(tuple);
+}
+
+/*
  *		renametrig		- changes the name of a trigger on a relation
  *
  *		trigger name is changed in trigger catalog.
@@ -1165,21 +1198,26 @@ get_trigger_oid(Oid relid, const char *trigname, bool missing_ok)
  *		update row in catalog
  */
 void
-renametrig(Oid relid,
-		   const char *oldname,
-		   const char *newname)
+renametrig(RenameStmt *stmt)
 {
 	Relation	targetrel;
 	Relation	tgrel;
 	HeapTuple	tuple;
 	SysScanDesc tgscan;
 	ScanKeyData key[2];
+	Oid			relid;
 
 	/*
-	 * Grab an exclusive lock on the target table, which we will NOT release
-	 * until end of transaction.
+	 * Look up name, check permissions, and acquire lock (which we will NOT
+	 * release until end of transaction).
 	 */
-	targetrel = heap_open(relid, AccessExclusiveLock);
+	relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock,
+									 false, false,
+									 RangeVarCallbackForRenameTrigger,
+									 NULL);
+
+	/* Have lock already, so just need to build relcache entry. */
+	targetrel = relation_open(relid, NoLock);
 
 	/*
 	 * Scan pg_trigger twice for existing triggers on relation.  We do this in
@@ -1202,14 +1240,14 @@ renametrig(Oid relid,
 	ScanKeyInit(&key[1],
 				Anum_pg_trigger_tgname,
 				BTEqualStrategyNumber, F_NAMEEQ,
-				PointerGetDatum(newname));
+				PointerGetDatum(stmt->newname));
 	tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true,
 								SnapshotNow, 2, key);
 	if (HeapTupleIsValid(tuple = systable_getnext(tgscan)))
 		ereport(ERROR,
 				(errcode(ERRCODE_DUPLICATE_OBJECT),
 				 errmsg("trigger \"%s\" for relation \"%s\" already exists",
-						newname, RelationGetRelationName(targetrel))));
+						stmt->newname, RelationGetRelationName(targetrel))));
 	systable_endscan(tgscan);
 
 	/*
@@ -1222,7 +1260,7 @@ renametrig(Oid relid,
 	ScanKeyInit(&key[1],
 				Anum_pg_trigger_tgname,
 				BTEqualStrategyNumber, F_NAMEEQ,
-				PointerGetDatum(oldname));
+				PointerGetDatum(stmt->subname));
 	tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true,
 								SnapshotNow, 2, key);
 	if (HeapTupleIsValid(tuple = systable_getnext(tgscan)))
@@ -1232,7 +1270,8 @@ renametrig(Oid relid,
 		 */
 		tuple = heap_copytuple(tuple);	/* need a modifiable copy */
 
-		namestrcpy(&((Form_pg_trigger) GETSTRUCT(tuple))->tgname, newname);
+		namestrcpy(&((Form_pg_trigger) GETSTRUCT(tuple))->tgname,
+				   stmt->newname);
 
 		simple_heap_update(tgrel, &tuple->t_self, tuple);
 
@@ -1251,7 +1290,7 @@ renametrig(Oid relid,
 		ereport(ERROR,
 				(errcode(ERRCODE_UNDEFINED_OBJECT),
 				 errmsg("trigger \"%s\" for table \"%s\" does not exist",
-						oldname, RelationGetRelationName(targetrel))));
+						stmt->subname, RelationGetRelationName(targetrel))));
 	}
 
 	systable_endscan(tgscan);
@@ -1261,7 +1300,7 @@ renametrig(Oid relid,
 	/*
 	 * Close rel, but keep exclusive lock!
 	 */
-	heap_close(targetrel, NoLock);
+	relation_close(targetrel, NoLock);
 }