From bd6776c7ff23c0fba7b1abc51713975e640a3830 Mon Sep 17 00:00:00 2001
From: Takuma Hoshiai <takuma.hoshiai@gmail.com>
Date: Sun, 18 Sep 2022 06:14:19 +0900
Subject: [PATCH] fix an irregular case of get_immv_def()

Add test case, when an argument of immvrelid is not IMMV oids.
---
 expected/pg_ivm.out | 18 ++++++++++++++++++
 pg_ivm.c            | 10 +++++++++-
 sql/pg_ivm.sql      |  5 +++++
 3 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/expected/pg_ivm.out b/expected/pg_ivm.out
index 46bffdd..ba0a3b0 100644
--- a/expected/pg_ivm.out
+++ b/expected/pg_ivm.out
@@ -1043,6 +1043,24 @@ DELETE FROM mv_ivm_1;
 ERROR:  cannot change materialized view "mv_ivm_1"
 TRUNCATE mv_ivm_1;
 ERROR:  cannot change materialized view "mv_ivm_1"
+-- get_immv_def function
+SELECT immvrelid, get_immv_def(immvrelid) FROM pg_ivm_immv ORDER BY 1;
+ immvrelid |           get_immv_def           
+-----------+----------------------------------
+ mv_ivm_1  |  SELECT a.i,                    +
+           |     a.j,                        +
+           |     b.k                         +
+           |    FROM (mv_base_a a            +
+           |      JOIN mv_base_b b USING (i))
+(1 row)
+
+-- mv_base_b is not immv
+SELECT 'mv_base_b'::regclass, get_immv_def('mv_base_b');
+ regclass  | get_immv_def 
+-----------+--------------
+ mv_base_b | 
+(1 row)
+
 DROP TABLE mv_base_b CASCADE;
 NOTICE:  drop cascades to 3 other objects
 DETAIL:  drop cascades to table mv_ivm_1
diff --git a/pg_ivm.c b/pg_ivm.c
index dc7e8fc..29b567b 100644
--- a/pg_ivm.c
+++ b/pg_ivm.c
@@ -330,12 +330,20 @@ get_immv_def(PG_FUNCTION_ARGS)
 {
 	Oid	matviewOid = PG_GETARG_OID(0);
 	Relation matviewRel = NULL;
-	char * querystring = NULL;
+	Query *query = NULL;
+	char *querystring = NULL;
 
 	matviewRel = table_open(matviewOid, AccessShareLock);
 	/* Make sure IMMV is a table. */
 	Assert(matviewRel->rd_rel->relkind == RELKIND_RELATION);
 
+	query = get_immv_query(matviewRel);
+	if (query == NULL)
+	{
+		table_close(matviewRel, NoLock);
+		PG_RETURN_TEXT_P(cstring_to_text(""));
+	}
+
 	querystring = pg_ivm_get_querydef(get_immv_query(matviewRel), false);
 
 	table_close(matviewRel, NoLock);
diff --git a/sql/pg_ivm.sql b/sql/pg_ivm.sql
index 32dfe14..6c6a9f4 100644
--- a/sql/pg_ivm.sql
+++ b/sql/pg_ivm.sql
@@ -460,5 +460,10 @@ UPDATE  mv_ivm_1 SET k = 1 WHERE i = 1;
 DELETE FROM mv_ivm_1;
 TRUNCATE mv_ivm_1;
 
+-- get_immv_def function
+SELECT immvrelid, get_immv_def(immvrelid) FROM pg_ivm_immv ORDER BY 1;
+-- mv_base_b is not immv
+SELECT 'mv_base_b'::regclass, get_immv_def('mv_base_b');
+
 DROP TABLE mv_base_b CASCADE;
 DROP TABLE mv_base_a CASCADE;