Re: [PATCH] DocBook: Avoid stdout junk with no man pages to compress

[Ulf Magnusson <ulfalizer.lkml@gmail.com>]

On Sun, Jul 12, 2015 at 04:36:53PM -0700, Jim Davis wrote:
> On Sun, Jul 12, 2015 at 2:59 PM, Ulf Magnusson <ulfalizer.lkml@gmail.com> wrote:
> > gzip would run as 'gzip -f' when no uncompressed man pages were found,
> > making it compress the (empty) stdin to stdout.
> 
> > --- a/Documentation/DocBook/Makefile
> > +++ b/Documentation/DocBook/Makefile
> > @@ -56,7 +56,7 @@ htmldocs: $(HTML)
> >
> >  MAN := $(patsubst %.xml, %.9, $(BOOKS))
> >  mandocs: $(MAN)
> > -       find $(obj)/man -name '*.9' | xargs gzip -f
> > +       find $(obj)/man -name '*.9' -exec gzip -f {} \;
> >
> >  installmandocs: mandocs
> >         mkdir -p /usr/local/man/man9/
> 
> That does get rid of the binary burp, but 'xargs gzip -f'  has been in
> the Makefile since January, and gzipping '\n' just started recently.
> So what's changed?
> 

No idea. I just assumed it had been broken since then, since the version
before d56fcf299fb4 (DocBook: Do not exceed argument list limit) looked
for *.9 files before running gzip:

mandocs: $(MAN)
	$(if $(wildcard $(obj)/man/*.9),gzip -f $(obj)/man/*.9)

> It looks like, for whatever reason, make installmandocs always ends up
> rerunning mandocs -- there's now a 'GEN  Documentation
> Docbook//v4l2.xml' printed, and that extra mandocs invocation is where
> the problematic second invocation of find is coming from.  I won't
> pretend to understand the Makefile flow to guess at why that's
> happening, but obviously 'make mandocs; make installmandocs' shouldn't
> need to regenerate things already generated.

I won't pretend to understand the Makefile flow either. Guess it might
be worth looking into v4l2.xml as well then. Could be some directory
shenanigans going on judging from the '//'.

> 
> In any event,
> 
> Tested-by: Jim Davis <jim.epost@gmail.com>
> 
> Jim

I just noticed the commit message only mentions the alternative
solutions and not the implemented solution. Could send a v2 that fixes
that, but I'll wait for more comments first.

Cheers,
Ulf