keeping track of local modifications

[perryh at pluto.rain.com]

> > Git and Mercurial cannot import Subversion $FreeBSD$ lines
> > so far, and you may end up submitting patches that include
> > unexpanded forms of the "$FreeBSD: xxxx $" text.  These will
> > fail to apply if they same patch touches nearby lines.
>
> Ahm, yes.  "sed -e's|$FreeBSD: [^$]* \$|$FreeBSD$|g'" should help
> in this case.

Not sure I understand what is meant by "unexpanded" here, since
it looks as if this sed example would convert an "expanded" form
-- containing the version info -- to an "unexpanded" one that
merely shows where that info should go.

Perhaps it's my ClearCase background showing through, but I'd think
it highly desirable for a patch to include what I think of as the
expanded tag line -- including the version info, as it appears in
the distributed files under /usr/src -- thereby explicitly showing
the version on which the patch is based (the "base contributor"
in ClearCase-speak).  This should greatly simplify merging in the
(likely) event that other development has occurred on the same file
in the meantime -- provided one is using a 3-way merge tool that
understands such things.