[RFC] git-format-patch options

It is often the case that "since <mine> head forked from <his> head" (quoting the manual page of git-format-patch), for various projects, some patches have been accepted and some have not.

I was wondering about the value of

  git-format-patch <commit-ish>

to output/prepare a diff patch between the indicated commit and its parent. As opposed to the current behaviour giving all changes between the indicated commit and HEAD.

So in effect the form above would become the trivial:

  git-format-patch <commit-ish>..HEAD

and

  git-format-patch <commit-ish>

would give the diff patch between the indicated commit and its parent.

?

    Luben