Re: [PATCH] diff: resurrect the traditional empty "diff --git" behaviour

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

Hi,

On Fri, 31 Aug 2007, Jeff King wrote:

> On Fri, Aug 31, 2007 at 01:13:42PM -0700, Junio C Hamano wrote:
> 
> > If you set diff.autorefreshindex configuration variable, it
> > squelches the empty "diff --git" output, and at the end of the
> > command, it automatically runs "update-index --refresh" without
> > even bothering the user.  In other words, with the configuration
> > variable set, people who do not care about the cache-dirtyness
> > do not even have to see the warning.
> 
> Nice. This is much more sane behavior, IMHO, and I think it should make 
> everyone happy.

I could even imagine that this will eventually become the standard 
behaviour.

> >  Same here.  This patch saw only very light testing, but I
> >  personally think is a sane thing to do before 1.5.3 final.
> 
> Passes my light testing as well, but I have a feeling we just tested the
> same things...;)
> 
> One question on the implementation (and remember that I am somewhat
> ignorant of the structure of this part of the code, so the answer may be
> "it's too ugly"): is there a good reason to refresh _after_ the diff?

We do not need to do it always.  After the diff, we know if the index 
needs refreshing.  Before, we don't.

> It seems like when we are looking through the working tree and index the 
> first time, we notice that the stat information doesn't match; why can't 
> we update it then? That would save an extra working tree traversal.

But that would be intrusive in the diff machinery IMHO.  It should stay as 
read-only as possible.

BTW I was a little concerned that the locking would fail in a read-only 
setup, and that git would die(), but that has been taken care of, so I 
have no objections left.

Thanks, Junio.

Ciao,
Dscho