I'm not sure if I'm reading your comment right, but if you're going to do something that might result in a mess (such as a merge or a rebase) the sane thing to

I'm not sure if I'm reading your comment right, but if you're going to do something that might result in a mess (such as a merge or a rebase) the sane thing to do is not to have anything uncommitted in your workdir; that way you can always retry, undo and experiment, and the VCS is doing exactly what it's supposed to be doing. It's something subversion can't do last I checked, so whenever I need to do a complicated operation with SVN, I import the local state into a git repo first :P