I found that when update bug, but the field not changed their values and click to update bottom, the last update is modified about bug. I think, there 2 possibilites, the first shouldn't changed the last update the bug and second this should be register in the history bug "unchanged". any option no is confuse. thanks

Confirmed also in current master.

One option is to introduce a return value in function history_log_event_direct (changed or not changed) and call bug_update_date only if the value has been set at least one time to true.

Another option is to build a list of changed fields in a first step, update just the changed fields in database, call history_log_event_direct only for changed fields.

thanks, I´m going to implement the both answers and select the better option for my bussines

Is this a common issue?