Merge or rebase certain branches on top of remotes

[JBYoshi]

This would only occur if Git can automatically merge them. I'd need a way to detect what branch to add, though, and whether to merge or rebase.

I'd also like to handle rebasing submodules, but JGit doesn't seem to provide a way to get the old and new commits from a rebase.

[JBYoshi]

Apparently it's more complex than I thought. It would require either a clean working directory (as in "index matches HEAD, working directory matches index") or support for multiple working directories, which JGit doesn't have. It would also mess up any programs using the working directory at the time.