Instead of rebasing from the commit below the current one and then setting the
current one to "edit", we rebase from the current one and insert a "break" after
it. In most cases the behavior is exactly the same as before, except that the
new method also works if the current commit is a merge commit. This is useful if
you want to create a new commit at the very beginning of your branch (by editing
the last commit before your branch).
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