[twic]

I agree that the situation where you need the changes in B to make the changes in A is both genuine and annoying!

I have often taken the stash A - change B - commit B - pop A - finish A route. If you know what changes to B you need, it's fine, but you're right, the changes to A can be useful context.

In that case, you can make the changes to B with the changes to A still around, then stash A, run the tests, commit, pop A, and continue. Then you can have the best of both worlds, and you still don't need to edit history.

If you just can't make the changes to B without the changes to A, then they probably belong in a single commit, and you've just identified a possible coupling that needs refactoring as a bonus.