• I run a terminal using koi8-r character set.
  In case of gnome-terminal, do "Terminal >Set Character Encoding>Cyrillic(KOI8-R)

• Start mysql like this:

  LANG=ru_RU.koi8r mysql -uroot test

• And create a stored function returning a binary string

  DROP FUNCTION IF EXISTS f1;

  CREATE FUNCTION f1() RETURNS BINARY RETURN (SELECT _binary'яп╠' AS я);

  SELECT ROUTINE_DEFINITION FROM INFORMATION_SCHEMA.ROUTINES WHERE ROUTINE_NAME='f1';

This SQL script returns:

+----------------------------+

| ROUTINE_DEFINITION         |

+----------------------------+

| RETURN (SELECT '???' AS я) |

+----------------------------+

Note, if I now run a new terminal using utf8 as a character set and run this query:

SELECT ROUTINE_DEFINITION FROM INFORMATION_SCHEMA.ROUTINES WHERE ROUTINE_NAME='f1';

it returns

+--------------------------------+

| ROUTINE_DEFINITION             |

+--------------------------------+

| RETURN (SELECT 'Ñб' AS я)     |

+--------------------------------+

The expected result would be to replace the literal to X'HHHH' notation.