Re: [PATCH] format-patch: add --filename-prefix to prepend a prefix to output file names

Nguyễn Thái Ngọc Duy  [off-list ref] writes:

I use git to manage patches in my Gentoo development. In Gentoo, all
ebuilds (another form of RPM spec) corresponding to different versions
of the same package are grouped into one directory. So patches for
each version usually have a prefix to separate them from ones for
other versions. With --filename-prefix it comes handy to produce such
patches, for example:

git format-patch --filename-prefix dbus-1.2.3- HEAD~5

will generate patches for dbus-1.2.3 for me, all starting with "dbus-1.2.3-".

This might be handy for RPM developers as well.

If this patch needs another round, I would prefer seeing the explanation
done in a different order.  When a busy person who is uninterested in
Gentoo starts reading the above paragraph, the patch will (incorrectly) be
dismissed with an "Ah, Gentoo specific feature?  Not interesting." after
reading the first two lines.  I.e. "Add X that does Y.  This is useful in
such and such situations because ...".

+--filename-prefix=.<pfx>::
+	Prepend specified prefix in front of generated filenames.

Hmm... ;-)

What happens when I feed a path with a slash in it with --filename-prefix?
We will fail in open/creat if the leading path does not exist?

I am not saying we must allow a slash in the prefix and create necessary
leading paths ourselves, nor we must check for a slash and fail in the
input validation phase, but I am wondering if we can have some clever way
to internally unify the handling of this new option with --outdir.

Heh, clever.  I wondered what the point of testing with --stdout was
for a patch that affects the generated filename.  The magic of --attach ;-)