Use correct input type for example UDR multi

[Ev3nt]

Summary

Invalid types conversion.

Details

When calling ExampleBCD::load, we pass a pointer to the FB_DEC34 data type, but in fact the memory referenced by the pointer is an ordinary int. This causes the crash.

PoC

A simple script that causes an error:

import os
import subprocess
import sys
from pathlib import Path

ISQL = Path("/home/user/repositories/firebird-6/gen/Debug/firebird/bin/isql")

def build_sql() -> str:
  return f"""
      connect localhost:employee user 'SYSDBA' password 'masterkey';
      set term ^;
      create function mult(a integer, b integer)
      returns integer
      external name 'udrcpp_example!mult'
      engine udr^
      set term ;^
      commit;
      select mult(2.49, -8) from rdb$database;
      quit;
      """

def run_isql(sql: str) -> int:
  proc = subprocess.run(
    [str(ISQL), "-q"],
    input=sql.encode()
  )
  print("returncode:", proc.returncode)
  if proc.returncode < 0:
    print(f"terminated by signal: {-proc.returncode}")
  return proc.returncode

def main():
  run_isql(build_sql())

if __name__ == "__main__":
  main()