Re: clean up m4sh.m4, then optimize AS_PATH_WALK

[Ralf Wildenhues]

Hi Eric, Stepan,

* Stepan Kasal wrote on Sun, Apr 02, 2006 at 12:49:25AM CEST:
> > > 2006-04-01  Eric Blake  <address@hidden>
> > > 
> > >   * lib/m4sugar/m4sh.m4 (_AS_PATH_WALK): Optimize nonexistent
> > >   directories, unless optional third argument supplied.
> > >   (AS_UNAME): Don't optimize PATH walk.
> > 
> > I committed this one exactly as submitted.
> 
> ... which introduced a bug in autotest. 

So this patch was not only not fixing a bug, but merely an optimization,
but also introducing a bug.

Please leave the introduction of bugs to post 2.60 for now, unless you
also fix actual bugs.  Micro-optimization doesn't count for the latter.
Thank you.

FWIW, I have been holding back some "optimizations" for quite a while,
for exactly this reason.

Cheers,
Ralf