[PATCH] git-status: Detect copies as well as renames

["Björn Steinbrink" <B.Steinbrink@gmx.de>]

Signed-off-by: Björn Steinbrink <B.Steinbrink@gmx.de>
---
On 2008.10.10 08:44:08 -0700, Junio C Hamano wrote:
> "Michael P. Soulier" <msoulier@digitaltorque.ca> writes:
> 
> > #       renamed:    templates/scrc/index.html -> templates/scrc/cres_taps.html
> > #       modified:   templates/scrc/index.html
> >
> > Looking at the last two lines here, there is obviously an issue.
> 
> I am puzzled.
> 
> Looking at wt-status.c "renamed: A -> B" will be shown only when A and
> B are similar enough *and* there is no A remaining in the final
> result, and in such a case, "modified: A" should not be shown.
> Because git does not care how you created B (IOW, it does not matter
> if B was typed from scratch with copying and pasting, or created by
> copying and editing), the "renamed: A -> B" entry itself is not
> surprising nor look like a bug at all, but its presense at the same
> time as "modified: A" does feel very fishy.

Maybe something like this is required? The "1" meant that only renames
were to be detected, so I'm quite puzzled why it detects copies in some
cases at all. At least some trivial:

cp Makefile Makefile2
echo 123 >> Makefile
git add Makefile*

Now correctly shows the Makefile2 being a copy of Makefile, while the
old behaviour was to simply show it as a new file. _BUT_ when you also
did:

git mv Makefile Makefile3

You see a rename of Makefile and a copy of Makefile. Even though we
didn't request copy detection... Hu?

I feel like stabbing in the dark though, so I intentionally left out a
description in the commit message that tells why this change is good. I
simply have no idea, it just _felt_ better. ;-)

Björn

 wt-status.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/wt-status.c b/wt-status.c
index 889e50f..3d645b9 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -210,7 +210,7 @@ static void wt_status_print_updated(struct wt_status *s)
 	rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 	rev.diffopt.format_callback = wt_status_print_updated_cb;
 	rev.diffopt.format_callback_data = s;
-	rev.diffopt.detect_rename = 1;
+	rev.diffopt.detect_rename = DIFF_DETECT_COPY;
 	rev.diffopt.rename_limit = 200;
 	rev.diffopt.break_opt = 0;
 	run_diff_index(&rev, 1);
@@ -310,7 +310,7 @@ static void wt_status_print_verbose(struct wt_status *s)
 	init_revisions(&rev, NULL);
 	setup_revisions(0, NULL, &rev, s->reference);
 	rev.diffopt.output_format |= DIFF_FORMAT_PATCH;
-	rev.diffopt.detect_rename = 1;
+	rev.diffopt.detect_rename = DIFF_DETECT_COPY;
 	rev.diffopt.file = s->fp;
 	rev.diffopt.close_file = 0;
 	run_diff_index(&rev, 1);
-- 
1.6.0.2.307.gc427.dirty