Submitted by: @ibprovider

Server Name :Firebird
Server Version :2.5.0.25856
Client Name :Firebird SQL Server
Client Version :2.5.0.25856
Database ODS :11.2
Database Dialect:3

---
CREATE PROCEDURE SP_TMP_007_298 (IN1 TIMESTAMP NOT NULL = CURRENT_TIMESTAMP)
AS
DECLARE VARIABLE X INTEGER;
BEGIN
X=0;
END

---
select f.rdb$default_source
from rdb$procedure_parameters pp
join rdb$fields f
on pp.rdb$field_source=f.rdb$field_name
where pp.rdb$procedure_name = 'SP_TMP_007_298'

--- Result
= CURRENT_TIMESTAMP)

I think, result should be
= CURRENT_TIMESTAMP

----
FB 2.1.3.18185 works correctly

Commits: 8d8a8b5 b31f3bc 15a9a2b

====== Test Details ======

Default values for fields that are defined NOT via domains (i.e. those which are shown as 'RDB$nnn' in the fileld rdb$procedure_parameters.rdb$default_source) are stored differently in 2.5 vs 3.0:
1) 2.5 -- in rdb$fields.rdb$default_source;
2) 3.0 -- in rdb$procedure_parameters.rdb$default_source
-- see expected out in the test.