Karma and bug activity missing when bugs are updated by creating a release

When a release is created from a milestone all the fix committed bugs are updated to fix released, but the events are not recorded in the bug history, nor is the assigned engineer awarded karma. The problem is in Milestone.createProductRelease(). The loop of bugtasks must use snapshot and ObjectModifiedEvent to ensure the subscribers are notified.

        for bugtask in self.open_bugtasks:
            if bugtask.status == BugTaskStatus.FIXCOMMITTED:
                original_bugtask = Snapshot(
                    bugtask, providing=providedBy(bugtask))
                bugtask.transitionToStatus(BugTaskStatus.FIXRELEASED, owner)
                ObjectModifiedEvent(
                    object=bugtask, object_before_modification=original_bugtask,
                    edited_fields=['status']))