Fix convertiong regprocedure to text, small refactoring

Author: maksm90

hash.sql

@@ -141,7 +141,7 @@ BEGIN
 
 	/* Fetch init_callback from 'params' table */
 	WITH stub_callback(stub) as (values (0))
-	SELECT coalesce(init_callback, NULL)
+	SELECT init_callback
 	FROM stub_callback
 	LEFT JOIN @extschema@.pathman_config_params AS params
 	ON params.partrel = parent_relid

init.sql

@@ -52,7 +52,7 @@ CREATE TABLE IF NOT EXISTS @extschema@.pathman_config_params (
 	partrel			REGCLASS NOT NULL PRIMARY KEY,
 	enable_parent	BOOLEAN NOT NULL DEFAULT FALSE,
 	auto			BOOLEAN NOT NULL DEFAULT TRUE,
-	init_callback	TEXT,
+	init_callback	TEXT DEFAULT NULL,
 	spawn_using_bgw	BOOLEAN NOT NULL DEFAULT FALSE
 
 	CHECK (@extschema@.validate_part_callback(init_callback)) /* check signature */
@@ -157,12 +157,21 @@ CREATE OR REPLACE FUNCTION @extschema@.set_init_callback(
 	callback	REGPROC DEFAULT 0)
 RETURNS VOID AS
 $$
+DECLARE
+	regproc_text	TEXT;
 BEGIN
-	PERFORM @extschema@.pathman_set_param(relation, 'init_callback',
-		CASE WHEN callback <> 0
-			THEN regprocedureout(callback)::text
-			ELSE NULL END);
-
+	IF callback != 0 THEN
+		EXECUTE 'SELECT quote_ident(nspname) || ''.'' || quote_ident(proname)'
+				'	|| ''('' || (SELECT string_agg(x.argtype::regtype::text, '','')'
+				'				 FROM unnest(proargtypes) AS x(argtype))'
+				'	|| '')'''
+				'FROM pg_proc p JOIN pg_namespace n ON n.oid=p.pronamespace WHERE p.oid=$1'
+			INTO regproc_text
+			USING callback;
+	ELSE
+		regproc_text := NULL;
+	END IF;
+	PERFORM @extschema@.pathman_set_param(relation, 'init_callback', regproc_text);
 END
 $$
 LANGUAGE plpgsql STRICT;

range.sql

@@ -1051,7 +1051,7 @@ BEGIN
 
 	/* Fetch init_callback from 'params' table */
 	WITH stub_callback(stub) as (values (0))
-	SELECT coalesce(init_callback, NULL)
+	SELECT init_callback
 	FROM stub_callback
 	LEFT JOIN @extschema@.pathman_config_params AS params
 	ON params.partrel = parent_relid

src/partition_creation.c

@@ -1394,23 +1394,23 @@ make_int_value_struct(int int_val)
 /*
  * Utility function that converts signature of procedure into regprocedure.
  *
- * Precondition: proname_args != NULL.
+ * Precondition: proc_signature != NULL.
  *
  * Returns InvalidOid if proname_args is not found.
  * Raise error if it's incorrect.
  */
 static Oid
-text2regprocedure(text *proname_args)
+text2regprocedure(text *proc_signature)
 {
 	FunctionCallInfoData fcinfo;
 	Datum           result;
 
 	InitFunctionCallInfoData(fcinfo, NULL, 1, InvalidOid, NULL, NULL);
 
 #if PG_VERSION_NUM >= 90600
-	fcinfo.arg[0] = PointerGetDatum(proname_args);
+	fcinfo.arg[0] = PointerGetDatum(proc_signature);
 #else
-	fcinfo.arg[0] = CStringGetDatum(text_to_cstring(proname_args));
+	fcinfo.arg[0] = CStringGetDatum(text_to_cstring(proc_signature));
 #endif
 	fcinfo.argnull[0] = false;