Wrong name in error message when unknown namespace is passed into RDB$SET_CONTEXT()

[hvlad]

SELECT RDB$SET_CONTEXT('NS', 'VARNAME', 2) FROM RDB$DATABASE;

Statement failed, SQLSTATE = HY000
Invalid namespace name VARNAME passed to RDB$SET_CONTEXT

Should be:

Statement failed, SQLSTATE = HY000
Invalid namespace name NS passed to RDB$SET_CONTEXT