Fix pg_identify_object_as_address() with event triggers

Attempting to use this function with event triggers failed, as, since
its introduction in a676201, this code has never associated an object
name with event triggers.  This addresses the failure by adding the
event trigger name to the set defining its object address.

Note that regression tests are added within event_trigger and not
object_address to avoid issues with concurrent connections in parallel
schedules.

Author: Joel Jacobson
Discussion: https://postgr.es/m/3c905e77-a026-46ae-8835-c3f6cd1d24c8@www.fastmail.com
Backpatch-through: 9.6

3 files changed, 33 insertions, 6 deletions

diff --git a/src/backend/catalog/objectaddress.c b/src/backend/catalog/objectaddress.c
index 6d88b690d87..ad9740098e4 100644
--- a/src/backend/catalog/objectaddress.c
+++ b/src/backend/catalog/objectaddress.c
@@ -5607,10 +5607,7 @@ getObjectIdentityParts(const ObjectAddress *object,
 			{
 				HeapTuple	tup;
 				Form_pg_event_trigger trigForm;
-
-				/* no objname support here */
-				if (objname)
-					*objname = NIL;
+				char	   *evtname;
 
 				tup = SearchSysCache1(EVENTTRIGGEROID,
 									  ObjectIdGetDatum(object->objectId));
@@ -5622,8 +5619,10 @@ getObjectIdentityParts(const ObjectAddress *object,
 					break;
 				}
 				trigForm = (Form_pg_event_trigger) GETSTRUCT(tup);
-				appendStringInfoString(&buffer,
-									   quote_identifier(NameStr(trigForm->evtname)));
+				evtname = NameStr(trigForm->evtname);
+				appendStringInfoString(&buffer, quote_identifier(evtname));
+				if (objname)
+					*objname = list_make1(evtname);
 				ReleaseSysCache(tup);
 				break;
 			}
diff --git a/src/test/regress/expected/event_trigger.out b/src/test/regress/expected/event_trigger.out
index bdd0ffcdaf3..369f3d7d84f 100644
--- a/src/test/regress/expected/event_trigger.out
+++ b/src/test/regress/expected/event_trigger.out
@@ -533,6 +533,23 @@ DROP POLICY p2 ON event_trigger_test;
 NOTICE:  DROP POLICY - ddl_command_start
 NOTICE:  DROP POLICY - sql_drop
 NOTICE:  DROP POLICY - ddl_command_end
+-- Check the object addresses of all the event triggers.
+SELECT
+    e.evtname,
+    pg_describe_object('pg_event_trigger'::regclass, e.oid, 0) as descr,
+    b.type, b.object_names, b.object_args,
+    pg_identify_object(a.classid, a.objid, a.objsubid) as ident
+  FROM pg_event_trigger as e,
+    LATERAL pg_identify_object_as_address('pg_event_trigger'::regclass, e.oid, 0) as b,
+    LATERAL pg_get_object_address(b.type, b.object_names, b.object_args) as a
+  ORDER BY e.evtname;
+      evtname      |              descr              |     type      |    object_names     | object_args |                         ident                          
+-------------------+---------------------------------+---------------+---------------------+-------------+--------------------------------------------------------
+ end_rls_command   | event trigger end_rls_command   | event trigger | {end_rls_command}   | {}          | ("event trigger",,end_rls_command,end_rls_command)
+ sql_drop_command  | event trigger sql_drop_command  | event trigger | {sql_drop_command}  | {}          | ("event trigger",,sql_drop_command,sql_drop_command)
+ start_rls_command | event trigger start_rls_command | event trigger | {start_rls_command} | {}          | ("event trigger",,start_rls_command,start_rls_command)
+(3 rows)
+
 DROP EVENT TRIGGER start_rls_command;
 DROP EVENT TRIGGER end_rls_command;
 DROP EVENT TRIGGER sql_drop_command;
diff --git a/src/test/regress/sql/event_trigger.sql b/src/test/regress/sql/event_trigger.sql
index 18b2a267cbe..e79c5f0b5dc 100644
--- a/src/test/regress/sql/event_trigger.sql
+++ b/src/test/regress/sql/event_trigger.sql
@@ -426,6 +426,17 @@ ALTER POLICY p1 ON event_trigger_test USING (TRUE);
 ALTER POLICY p1 ON event_trigger_test RENAME TO p2;
 DROP POLICY p2 ON event_trigger_test;
 
+-- Check the object addresses of all the event triggers.
+SELECT
+    e.evtname,
+    pg_describe_object('pg_event_trigger'::regclass, e.oid, 0) as descr,
+    b.type, b.object_names, b.object_args,
+    pg_identify_object(a.classid, a.objid, a.objsubid) as ident
+  FROM pg_event_trigger as e,
+    LATERAL pg_identify_object_as_address('pg_event_trigger'::regclass, e.oid, 0) as b,
+    LATERAL pg_get_object_address(b.type, b.object_names, b.object_args) as a
+  ORDER BY e.evtname;
+
 DROP EVENT TRIGGER start_rls_command;
 DROP EVENT TRIGGER end_rls_command;
 DROP EVENT TRIGGER sql_drop_command;