Re: [PATCH 2/4] t4011: illustrate "diff-index -p" on stat-dirty paths

From: Junio C Hamano <gitster@pobox.com>
Date: Mar 1, 2012, 16:18 UTC
Message-ID: <7vzkc0nvlk.fsf@alter.siamese.dyndns.org>
In-Reply-To: <87399slmh4.fsf@thomas.inf.ethz.ch>

Thomas Rast <trast@inf.ethz.ch> writes:

Show 6 quoted lines

> If that analysis is correct, then
>
>   we do not show any "diff --git" header for blobs whose true contents
>   are different but compares the same when whitespaces are ignored
>
> is not what is going on here; the blobs have exactly the same content.

True; an earlier draft actually had an 'echo " xyzzy" >nitfol' in there, but it meant that it needed another annoying 'sleep 3' (I could have used test-chmtime), so the test was updated but the above description stayed.

> The difference is that
>
> * without -w, the code "knows" from the lstat() data that the files are
>   different, prints a header, and then fails to find any differences;

Correct. Those quotes around "knows" are the most important ;-)

The code incorrectly thinks the stat dirtyness is all that it "knows"; even though it has a way to act on a better knowledge from the xdiff these days, it does not utilize it.

Show 9 quoted lines

> * with -w, the code correctly holds off on printing anything since it
>   will invariably have to inspect the contents beforehand.
>
> So perhaps you can say
>
>   Illustrate this current behaviour.  Also demonstrate that with the
>   "-w" option, we (correctly) hold off showing a "diff --git" header
>   until actual differences have been found.  This also suppresses the
>   header for merely stat-dirty files, which is inconsistent.

That is much better; thanks.