Can't backup/restore database from v3 to v4 with SEC$USER_NAME field longer than 10 characters

[dmitry-starodubov]

If I have such a simple database

CREATE TABLE T (ID INTEGER NOT NULL,
USER_NAME SEC$USER_NAME,
PASSWD VARCHAR(256) CHARACTER SET OCTETS,
ALG VARCHAR(32) CHARACTER SET UNICODE_FSS);

insert into t values(1, 'aaabbbcccddd', '12345678', '123');

I can backup/restore in on v3.
But when I try to restore backup from v3 on v4 I get an error:
gbak: ERROR:arithmetic exception, numeric overflow, or string truncation
gbak: ERROR: string right truncation
gbak: ERROR: expected length 10, actual 12
gbak: ERROR:gds_$send failed
gbak:Exiting before completion due to errors

Because maximum length of USER_NAME field is calculated wrong.

[sim1984]

v3 and v4, the SEC$USER_NAME domain has a different definition

CREATE DOMAIN SEC$USER_NAME AS
VARCHAR(31) CHARACTER SET UNICODE_FSS;

vs

CREATE DOMAIN SEC$USER_NAME AS
VARCHAR(63) CHARACTER SET UTF8;

[aafemt]

Both of them should be enough for 12 characters. Expected 10 in the error message is strange.