Ambiguous sha-1 during a rebase

Hi,

Something interesting happened to me. I was in the middle of an interactive rebase, and after a --continue, I got:

error: short SHA1 e34ff55 is ambiguous. fatal: Needed a single revision Invalid commit name: e34ff55

One thing that happened, is that, while running that interactive rebase, I /also/ did a `git remote update` from an other shell, which, I guess, happened to have imported another object that made e34ff55 ambiguous.

Should git-rebase use full sha-1s under the hood to avoid these type of races?

Relatedly, having looked up the ambiguity, it turns out the other object that fits the same short sha1 is a tree... maybe git should be able to disambiguate in that case, since it was looking for a commit, and there's only one commit with that short sha1?

Mike