importer collides when tag not on mainline

[James Westby]

In the following situation:

  * person1 prepares a new version, tags with "mark-uploaded"
  * person2 sponsors this change by merging to trunk, uploads, pushes and doesn't "mark-uploaded"

the importer will collide.

It finds the tag on the non-mainline revision, checks that it matches the package, records that it was ok,
continues, then finds that the tip of trunk doesn't have the revid of the tagged version and fails.

It should either change the point where it actually deals with the collision to check the tagged
revision, not the tip, or it should move the tag to the mainline revision when it does the check
at the start (provided no changes were introduced in the merge obviously).

Thanks,

James

[James Westby (james-w)]

Max pointed out that if it moves the tag it will have to take care to cause it to move
on LP as well.

Thanks,

James