Submitted by: @AlexPeshkoff

#⁠ ./isql employee
Database: employee
SQL> grant "RDB$ADMIN" to alex;

With role RDB$ADMIN I get message from the system trigger:

#⁠ ./isql -user alex -pas alex employee -role 'rdb$admin'
Database: employee, User: alex, Role: RDB$ADMIN
SQL> select * from a; -- user alex has no explicit / public grants on table A, i.e. for select it works
SQL> grant all on a to man1;
Statement failed, SQLSTATE = 42000
unsuccessful metadata update
-STORE RDB$USER_PRIVILEGES failed in grant
-action cancelled by trigger (2) to preserve data integrity
-user does not have GRANT privileges for operation

Without role RDB$ADMIN I get expected message:

#⁠ ./isql -user alex -pas alex employee
Database: employee, User: alex
SQL> grant all on a to man1;
Statement failed, SQLSTATE = 42000
unsuccessful metadata update
-no S privilege with grant option on table/view A

Commits: 3606706 386ad2c