Re: [PATCH] Re-re-re-fix common tail optimization

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

Hi,

On Mon, 17 Dec 2007, Wincent Colaiuta wrote:

> El 16/12/2007, a las 23:29, Jeff King escribi?:
> 
> > On Sun, Dec 16, 2007 at 02:23:27PM -0800, Junio C Hamano wrote:
> > 
> > > > Aren't we using "git diff" for the second diff there nowadays?
> > > 
> > > Some people seem to think that is a good idea, but I generally do 
> > > not like using "git diff" between expect and actual (both untracked) 
> > > inside tests.  The last "diff" is about validating what git does and 
> > > using "git diff" there would make the test meaningless when "git 
> > > diff" itself is broken.
> > 
> > I think that is a valid concern. But ISTR that were some issues with 
> > using GNU diff. Commit 5bd74506 mentions getting rid of the dependency 
> > in all existing tests, but gives no reason.
> 
> I'd say it's safe and sensible to use "git diff" in all tests *except* 
> for tests of "git diff" itself.

To the contrary.  It has to test "git diff", so it must use "git diff".  
As for the reference output: we include the expected diffs as texts, and 
therefore do not really have to rely on having GNU diff installed.

Besides, we cannot even test the goodies like "rename from" by comparing 
to GNU diff's output.

Ciao,
Dscho