marking a bug as duplicate has the effect of hiding any tasks that were uniquely on the duplicate

[Emmet Hikory]

When a bug has multiple bug tasks, and the bug is marked as a duplicate of a bug with a smaller number of tasks, the extra tasks are then unavailable for editing (as it is a duplicate), but not pushed to the duplicated bugs. As a result bug tasks become either lost or unavailable for update.

Observed Behaviour:
    A bug is opened, with a single bug task on a package
    Another bug is opened with bug tasks on two packages
    The second bug is marked as a duplicate of the first
    The tasks on the second bug become disabled due to duplication
    The first bug does not contain a task for the second package

Desired Behaviour:
    A bug is opened, with a single bug task on a package
    Another bug is opened with bug tasks on two packages
    The second bug is marked as a duplicate of the first
    The first bug's bug tasks are updated to include the second bug task from the second bug
    The tasks on the second bug become disabled due to duplication
    The first bug lists all tasks with status for all duplicates

Corollary desired behaviour:
    If a bug task is created due to duplication, and the duplication later removed, and there has been no update activity on the automatically created task, the automatic task should be removed from the original bug.

[Matthew Paul Thomas (mpt)]

Probably this should be implemented at the same time as bug 30537.

[Emmet Hikory (persia)]

The subscriber merge portion of 30537 is already complete. I'm not opposed to waiting for the spec, but certainly won't complain if the individual portions of 30537 (including this) are completed separately as time allows.

[Robert Collins (lifeless)]

I think that this needs a prompt rather than automatic merging; its up to folk doing a merge to say which is the most representative bug, and to merge any metadata that isn't amenable to automatic merging. Given that bugtasks can't be deleted (at the moment) I hesitate to merge tasks.