bug deleting "unmerged" branch (2.12.3)

Hi!

During a rebase that turned out to be heavier than expected 8-( I decided to keep the old branch by creating a temporary branch name to the commit of the branch to rebase (which was still the old commit ID at that time). When done rebasing, I attached a new name to the new (rebased) branch, deleted the old name (pointing at the same rebase commit), then recreated the old branch from the temporary branch name (created to remember the commit id). When I wanted to delete the temporary branch (which is of no use now), I got a message that the branch is unmerged. I think if more than one branches are pointing to the same commit, one should be allowed to delete all but the last one without warning. Do you agree?

Regards, Ulrich