[PATCH] Fix trigger argument propagation to child partitions

commit eb33c2cc0047bee6fb6ae20fd11aec438c3463da
Author: Patrick McHardy <kaber@trash.net>
Date:   Tue Jul 9 14:41:21 2019 +0200

    Fix trigger argument propagation to child partitions
    
    When creating a trigger on a partitioned table, the trigger is
    propagated to child partitions. However arguments specified for the
    trigger function are not propagated, leading to the trigger function
    being called without any arguments.
    
    Similarly, when attaching a new partition to a partitioned table, the
    trigger is copied without arguments.
    
    Fix this by:
    
    - Passing the original argument list to CreateTrigger when creating
      triggers for existing partitions.
    
    - Reconstructing the original argument list from the heap and passing it
      to CreateTrigger when creating triggers for newly attached partitions.
    
    Additionally add a simple regression test for both cases.
    
    Introduced in 86f575948c7.

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 5c278463c6..655d39ef71 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -15145,6 +15145,7 @@ CloneRowTriggersToPartition(Relation parent, Relation partition)
 		Datum		value;
 		bool		isnull;
 		List	   *cols = NIL;
+		List	   *args = NIL;
 		MemoryContext oldcxt;
 
 		/*
@@ -15209,11 +15210,28 @@ CloneRowTriggersToPartition(Relation parent, Relation partition)
 			}
 		}
 
+		/* Reconstruct trigger arguments list. */
+		if (trigForm->tgnargs > 0)
+		{
+			char 	   *p;
+			int			i;
+
+			value = heap_getattr(tuple, Anum_pg_trigger_tgargs,
+								 RelationGetDescr(pg_trigger), &isnull);
+			p = (char *) VARDATA_ANY(DatumGetByteaPP(value));
+
+			for (i = 0; i < trigForm->tgnargs; i++)
+			{
+				args = lappend(args, makeString(pstrdup(p)));
+				p += strlen(p) + 1;
+			}
+		}
+
 		trigStmt = makeNode(CreateTrigStmt);
 		trigStmt->trigname = NameStr(trigForm->tgname);
 		trigStmt->relation = NULL;
 		trigStmt->funcname = NULL;	/* passed separately */
-		trigStmt->args = NULL;	/* passed separately */
+		trigStmt->args = args;
 		trigStmt->row = true;
 		trigStmt->timing = trigForm->tgtype & TRIGGER_TYPE_TIMING_MASK;
 		trigStmt->events = trigForm->tgtype & TRIGGER_TYPE_EVENT_MASK;
diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c
index f6c7a3fefc..a716827c77 100644
--- a/src/backend/commands/trigger.c
+++ b/src/backend/commands/trigger.c
@@ -1153,7 +1153,6 @@ CreateTrigger(CreateTrigStmt *stmt, const char *queryString,
 			 */
 			childStmt = (CreateTrigStmt *) copyObject(stmt);
 			childStmt->funcname = NIL;
-			childStmt->args = NIL;
 			childStmt->whenClause = NULL;
 
 			/* If there is a WHEN clause, create a modified copy of it */
diff --git a/src/test/regress/expected/triggers.out b/src/test/regress/expected/triggers.out
index 31dbc9bcfc..a7661807c0 100644
--- a/src/test/regress/expected/triggers.out
+++ b/src/test/regress/expected/triggers.out
@@ -2092,6 +2092,26 @@ NOTICE:  trigger zzz on parted_trig_1_1 AFTER INSERT for ROW
 NOTICE:  trigger bbb on parted_trig_2 AFTER INSERT for ROW
 NOTICE:  trigger zzz on parted_trig_2 AFTER INSERT for ROW
 drop table parted_trig;
+-- Verify propagation of trigger arguments to partitions
+create table parted_trig (a int) partition by list (a);
+create table parted_trig1 partition of parted_trig for values in (1);
+create or replace function trigger_notice() returns trigger as $$
+  declare
+    arg1 text = TG_ARGV[0];
+    arg2 integer = TG_ARGV[1];
+  begin
+    raise notice 'trigger % on % % % for % args % %', TG_NAME, TG_TABLE_NAME, TG_WHEN, TG_OP, TG_LEVEL, arg1, arg2;
+    return null;
+  end;
+  $$ language plpgsql;
+create trigger aaa after insert on parted_trig for each row execute procedure trigger_notice('text', 1);
+insert into parted_trig values (1);
+NOTICE:  trigger aaa on parted_trig1 AFTER INSERT for ROW args text 1
+-- Verify propagation of trigger arguments to partitions attached after creating trigger
+create table parted_trig2 partition of parted_trig for values in (2);
+insert into parted_trig values (2);
+NOTICE:  trigger aaa on parted_trig2 AFTER INSERT for ROW args text 1
+drop table parted_trig;
 -- test irregular partitions (i.e., different column definitions),
 -- including that the WHEN clause works
 create function bark(text) returns bool language plpgsql immutable
diff --git a/src/test/regress/sql/triggers.sql b/src/test/regress/sql/triggers.sql
index 60b3e22c5c..909d403c62 100644
--- a/src/test/regress/sql/triggers.sql
+++ b/src/test/regress/sql/triggers.sql
@@ -1465,6 +1465,26 @@ create trigger qqq after insert on parted_trig_1_1 for each row execute procedur
 insert into parted_trig values (50), (1500);
 drop table parted_trig;
 
+-- Verify propagation of trigger arguments to partitions
+create table parted_trig (a int) partition by list (a);
+create table parted_trig1 partition of parted_trig for values in (1);
+create or replace function trigger_notice() returns trigger as $$
+  declare
+    arg1 text = TG_ARGV[0];
+    arg2 integer = TG_ARGV[1];
+  begin
+    raise notice 'trigger % on % % % for % args % %', TG_NAME, TG_TABLE_NAME, TG_WHEN, TG_OP, TG_LEVEL, arg1, arg2;
+    return null;
+  end;
+  $$ language plpgsql;
+create trigger aaa after insert on parted_trig for each row execute procedure trigger_notice('text', 1);
+insert into parted_trig values (1);
+
+-- Verify propagation of trigger arguments to partitions attached after creating trigger
+create table parted_trig2 partition of parted_trig for values in (2);
+insert into parted_trig values (2);
+drop table parted_trig;
+
 -- test irregular partitions (i.e., different column definitions),
 -- including that the WHEN clause works
 create function bark(text) returns bool language plpgsql immutable