Re: Diff Mode: Can I apply a difference to a buffer of my choosing?

[Stefan Monnier]

> .  I have loaded cc-defs.el.diff into a buffer in Diff Mode.  I want to
> apply one of its diffs to a buffer (coincidentally also called
> cc-defs.el).  However, when I try C-c C-a (`diff-apply-hunk'), Emacs
> loads a different version of cc-defs.el, and applies the patch to that.

diff-mode basically looks at the diff's header (or "Index:" line) to find
the file name to which the patch should be applied, then does find-file on
that file to get the buffer.

So you can try to get what you want, by doing a M-x cd in the diff's buffer
before C-s C-a (presumaing the diff's header uses relative path names).

> Is there any convenient way of associating cc-defs.el.diff with the
> buffer I want to change?

In Emacs-CVS, I've added a command diff-tell-file-name to do just that (tho
it still doesn't allow you to bind to a buffer, only to a filename).

In previous versions, you can do is M-x cd RET /some/where/else since if
diff-mode can't find the file on its own, it then asks you to enter the
destination file name interactively.


        Stefan