Fix ancient get_object_address_opf_member bug

The original coding was trying to use a TypeName as a string Value,
which doesn't work; an oversight in my commit a61fd533.  Repair.

Also, make sure we cover the broken case in the relevant test script.

Backpatch to 9.5.

Discussion: https://postgr.es/m/20170315151829.bhxsvrp75xdxhm3n@alvherre.pgsql

src/backend/catalog/objectaddress.c

@@ -1578,7 +1578,7 @@ get_object_address_opf_member(ObjectType objtype,
 	ObjectAddress address;
 	ListCell   *cell;
 	List	   *copy;
-	char	   *typenames[2];
+	TypeName   *typenames[2];
 	Oid			typeoids[2];
 	int			membernum;
 	int			i;
@@ -1600,7 +1600,7 @@ get_object_address_opf_member(ObjectType objtype,
 	{
 		ObjectAddress typaddr;
 
-		typenames[i] = strVal(lfirst(cell));
+		typenames[i] = (TypeName *) lfirst(cell);
 		typaddr = get_object_address_type(OBJECT_TYPE, cell, missing_ok);
 		typeoids[i] = typaddr.objectId;
 		if (++i >= 2)
@@ -1627,7 +1627,9 @@ get_object_address_opf_member(ObjectType objtype,
 						ereport(ERROR,
 								(errcode(ERRCODE_UNDEFINED_OBJECT),
 						  errmsg("operator %d (%s, %s) of %s does not exist",
-								 membernum, typenames[0], typenames[1],
+								 membernum,
+								 TypeNameToString(typenames[0]),
+								 TypeNameToString(typenames[1]),
 								 getObjectDescription(&famaddr))));
 				}
 				else
@@ -1656,7 +1658,9 @@ get_object_address_opf_member(ObjectType objtype,
 						ereport(ERROR,
 								(errcode(ERRCODE_UNDEFINED_OBJECT),
 						  errmsg("function %d (%s, %s) of %s does not exist",
-								 membernum, typenames[0], typenames[1],
+								 membernum,
+								 TypeNameToString(typenames[0]),
+								 TypeNameToString(typenames[1]),
 								 getObjectDescription(&famaddr))));
 				}
 				else
@@ -1993,7 +1997,7 @@ pg_get_object_address(PG_FUNCTION_ARGS)
 	}
 
 	/*
-	 * get_object_name is pretty sensitive to the length its input lists;
+	 * get_object_address is pretty sensitive to the length its input lists;
 	 * check that they're what it wants.
 	 */
 	switch (type)

src/test/regress/expected/object_address.out

@@ -65,6 +65,15 @@ WARNING:  error for sequence column: unsupported object type "sequence column"
 WARNING:  error for toast table column: unsupported object type "toast table column"
 WARNING:  error for view column: unsupported object type "view column"
 WARNING:  error for materialized view column: unsupported object type "materialized view column"
+-- miscellaneous other errors
+select * from pg_get_object_address('operator of access method', '{btree,integer_ops,1}', '{int4,bool}');
+ERROR:  operator 1 (int4, bool) of operator family integer_ops for access method btree does not exist
+select * from pg_get_object_address('operator of access method', '{btree,integer_ops,99}', '{int4,int4}');
+ERROR:  operator 99 (int4, int4) of operator family integer_ops for access method btree does not exist
+select * from pg_get_object_address('function of access method', '{btree,integer_ops,1}', '{int4,bool}');
+ERROR:  function 1 (int4, bool) of operator family integer_ops for access method btree does not exist
+select * from pg_get_object_address('function of access method', '{btree,integer_ops,99}', '{int4,int4}');
+ERROR:  function 99 (int4, int4) of operator family integer_ops for access method btree does not exist
 DO $$
 DECLARE
 	objtype text;

src/test/regress/sql/object_address.sql

@@ -62,6 +62,12 @@ BEGIN
 END;
 $$;
 
+-- miscellaneous other errors
+select * from pg_get_object_address('operator of access method', '{btree,integer_ops,1}', '{int4,bool}');
+select * from pg_get_object_address('operator of access method', '{btree,integer_ops,99}', '{int4,int4}');
+select * from pg_get_object_address('function of access method', '{btree,integer_ops,1}', '{int4,bool}');
+select * from pg_get_object_address('function of access method', '{btree,integer_ops,99}', '{int4,int4}');
+
 DO $$
 DECLARE
 	objtype text;