release-22.2: builtins: fix pg_function_is_visible for UDFs

pkg/sql/logictest/testdata/logic_test/pg_builtins

@@ -79,20 +79,26 @@ NULL
 statement ok
 CREATE TABLE is_visible(a int primary key);
 CREATE TYPE visible_type AS ENUM('a');
+CREATE FUNCTION visible_func() RETURNS INT LANGUAGE SQL AS $$ SELECT 1 $$;
 CREATE SCHEMA other;
 CREATE TABLE other.not_visible(a int primary key);
 CREATE TYPE other.not_visible_type AS ENUM('b');
+CREATE FUNCTION other.not_visible_func() RETURNS INT LANGUAGE SQL AS $$ SELECT 1 $$;
 CREATE DATABASE db2;
 SET DATABASE = db2;
 CREATE TABLE table_in_db2(a int primary key);
 CREATE TYPE type_in_db2 AS ENUM('c');
+CREATE FUNCTION func_in_db2() RETURNS INT LANGUAGE SQL AS $$ SELECT 1 $$;
 
 let $table_in_db2_id
 SELECT c.oid FROM pg_class c WHERE c.relname = 'table_in_db2';
 
 let $type_in_db2_id
 SELECT t.oid FROM pg_type t WHERE t.typname = 'type_in_db2';
 
+let $func_in_db2_id
+SELECT p.oid FROM pg_proc p WHERE p.proname = 'func_in_db2';
+
 statement ok
 SET DATABASE = test;
 
@@ -148,6 +154,31 @@ SELECT pg_type_is_visible(NULL)
 ----
 NULL
 
+query TB rowsort
+SELECT p.proname, pg_function_is_visible(p.oid)
+FROM pg_proc p
+WHERE p.proname IN ('array_length', 'visible_func', 'not_visible_func')
+----
+array_length      true
+visible_func      true
+not_visible_func  false
+
+# Looking up a function in a different database should return NULL.
+query B
+SELECT pg_function_is_visible($func_in_db2_id)
+----
+NULL
+
+# Looking up a non-existent OID should return NULL.
+query B
+SELECT pg_function_is_visible(1010101010)
+----
+NULL
+
+query B
+SELECT pg_function_is_visible(NULL)
+----
+NULL
 
 query TT
 SELECT pg_get_partkeydef(1), pg_get_partkeydef(NULL)
@@ -172,11 +203,11 @@ WHERE c.relname IN ('is_updatable', 'is_updatable_view', 'pg_class')
 ORDER BY c.oid, a.attnum
 ----
 relname            attname              oid         attnum  pg_relation_is_updatable  pg_column_is_updatable
-is_updatable       a                    120         1       28                        true
-is_updatable       b                    120         2       28                        true
-is_updatable       c                    120         3       28                        false
-is_updatable_view  a                    121         1       0                         false
-is_updatable_view  b                    121         2       0                         false
+is_updatable       a                    123         1       28                        true
+is_updatable       b                    123         2       28                        true
+is_updatable       c                    123         3       28                        false
+is_updatable_view  a                    124         1       0                         false
+is_updatable_view  b                    124         2       0                         false
 pg_class           oid                  4294967123  1       0                         false
 pg_class           relname              4294967123  2       0                         false
 pg_class           relnamespace         4294967123  3       0                         false

pkg/sql/sem/builtins/pg_builtins.go

@@ -1185,16 +1185,19 @@ SELECT description
 			Types:      tree.ArgTypes{{"oid", types.Oid}},
 			ReturnType: tree.FixedReturnType(types.Bool),
 			Fn: func(ctx *eval.Context, args tree.Datums) (tree.Datum, error) {
-				oid := tree.MustBeDOid(args[0])
+				dOid := tree.MustBeDOid(args[0])
 				t, err := ctx.Planner.QueryRowEx(
 					ctx.Ctx(), "pg_function_is_visible",
 					sessiondata.NoSessionDataOverride,
-					"SELECT * from pg_proc WHERE oid=$1 LIMIT 1", oid.Oid)
+					`SELECT n.nspname = ANY current_schemas(true) FROM pg_proc p
+           INNER JOIN pg_namespace n ON p.pronamespace = n.oid WHERE p.oid=$1 LIMIT 1`,
+					dOid,
+				)
 				if err != nil {
 					return nil, err
 				}
 				if t != nil {
-					return tree.DBoolTrue, nil
+					return tree.MakeDBool(tree.MustBeDBool(t[0])), nil
 				}
 				return tree.DNull, nil
 			},