Re: [PATCH] checkpatch: use patch subject when reading from stdin

[Joe Perches]

On Tue, 2019-10-15 at 08:49 +0200, Geert Uytterhoeven wrote:
> Hi Joe,

Rehi Geert.

> On Mon, Oct 14, 2019 at 4:48 PM Joe Perches <joe@xxxxxxxxxxx> wrote:
> > On Mon, 2019-10-14 at 11:20 +0200, Geert Uytterhoeven wrote:
[]
> > > I gave your solution a try.
> > > It only enables the reset-on-next-patch feature when using stdin.
> > > Thanks to the printed subject, it's now obvious to which patch a
> > > message applies to.
> > > However, the output is significantly different than when passing
> > > a split patch series.  Can this be improved upon?
> > > 
> > > Note that the only reason I'm using stdin is that I use formail to split
> > > a bundle in individual patches.  Once checkpatch supports bundles (or
> > > mboxes) containing multiple patches, there's no longer a need for
> > > using formail, and the reset-on-next-patch feature should be
> > > enabled unconditionally.
> > 
> > Using your collection of little tools idea,
> > why not write a trivial script like:
> > 
> >         grep "^Subject:" $1
> >         checkpatch.pl $1
> > 
> > and use that as the command line for formail
> > instead of adding unnecessary complexity to
> > checkpatch?
> 
> That would be another possibility.
> 
> But given more maintainers are starting to apply patchwork bundles (cfr.
> the workflows discussions), it makes sense to make their lives easier.

But given this particular change only works for stdin, then this
patch splitting idea wouldn't generically work.

> This is also useful for maintainers who save all patches to apply into a
> single mbox, and run checkpatch+git-am on that.

Which also wouldn't generally work for checkpatch <mbox>

> Summarized: git-am handles multiple patches, checkpatch requires
> splitting.

I still think it's better to introduce YA script that disaggregates
aggregated patches/emails and feeds each individual patch to
checkpatch rather than making checkpatch learn how to disaggregate.

Using "git mailsplit" as part of some additional script could work.