bugtrackers cannot be merged

[Graham Binns]

It's possible for two BugTracker records to be created for one actual remote bug tracker, thus:

1) Bob adds a bug tracker for bugs.example.com
2) Selma adds a comment to a bug in which she links to a bug on bugzilla.example.com. bugzilla.example.com is an alias for bugs.example.com, so the two bug tracker point to the same place.

This can lead to conflicts when syncing comments (let's assume that bugs.example.com has the Launchpad plugin installed) and could lead to us pulling the same comment down twice (though this should be caught by our duplicate-prevention code).

Admins should be able to merge two bug trackers together. This could work something like this:

1. On each bugtracker page, e.g. https://edge.launchpad.net/bugs/bugtrackers/gnome-bugs, there would be an option to "Merge this bug tracker with another."
2. Once you clicked on this link, Launchpad would ask you for the name or (remote) URL of the bugtracker into which you want to merge this one.
3. Once you've entered a URL Launchpad will:
 i) Move all BugWatches across to the target BugTracker
ii) Add the original bug tracker (i.e. the one on whose page you clicked "merge") as an alias on the target BugTracker
iii) Delete the old BugTracker.

[Robert Collins (lifeless)]

(Not escalating as I'm not aware of this having affected us.