Submitted by: @dyemanov

Assigned to: Claudio Valderrama C. (robocop)

Is related to QA39

The issue appears only if you're attempting to set the same comment value for a generator (other object types are not affected):

comment on generator G is 'asd';
commit;
comment on generator G is 'asd';
commit;
--
Cannot commit transaction:
This operation is not defined for system tables.
unsuccessful metadata update.
GENERATOR G.
Only can modify description for user generators.

The problem is inside vio.cpp::dfw_should_know() that returns true for the "nothing changed" condition.

Commits: aa756f7 9475e6b