Re: [PATCH] git status: do not require write permission

[Junio C Hamano <gitster@pobox.com>]

Junio C Hamano <gitster@pobox.com> writes:

> Jeff King <peff@peff.net> writes:
>
>> On Wed, Jan 20, 2010 at 01:06:17AM +0100, Johannes Schindelin wrote:
>>
>>> Today, git status played violin on my nerves for the very last time.
>>> There is no good reason, really none, for git status to require
>>> write permissions.  If the index is not up-to-date, so be it, I
>>> cannot commit anyway.
>>
>> I agree it is annoying, but this patch does not apply (and is no longer
>> needed) on master since the status-is-no-longer-commit-dry-run series
>> has been merged.
>>
>> I don't know if it is worth putting your fix onto maint.
>
> I think the patch itself makes sense,...

Actually, I think it was somewhat a selfish patch and forgot that the
codepath is shared with a mode of operation where we should guarantee
that the index is updated, namely "git commit".

I think this would be a good addition to 'maint'.  I am not sure if it is
worth forward-porting to "commit --dry-run", though.  On one hand, it
might show what would happen if you ran "commit" better (i.e. you will be
told that you cannot write into it), but it is debatable if that is the
reason why people may want to run "commit --dry-run".

-- >8 --
Subject: status: don't require the repository to be writable

We need to update the index before hooks run when actually making a
commit, but we shouldn't have to write the index when running "status".
If we can, then we have already spent cycles to refresh the index and
it is a waste not to write it out, but it is not a disaster if we cannot
write it out.  The main reason the user is running "git status" is to get
the "status", and refreshing the index is a mere side effect that we can
do without.

Discovery and initial attempted fix by Dscho.

---

 builtin-commit.c |   10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/builtin-commit.c b/builtin-commit.c
index 33aa593..83b7c35 100644
--- a/builtin-commit.c
+++ b/builtin-commit.c
@@ -278,11 +278,13 @@ static char *prepare_index(int argc, const char **argv, const char *prefix, int
 	 * We still need to refresh the index here.
 	 */
 	if (!pathspec || !*pathspec) {
-		fd = hold_locked_index(&index_lock, 1);
+		fd = hold_locked_index(&index_lock, !is_status);
 		refresh_cache(refresh_flags);
-		if (write_cache(fd, active_cache, active_nr) ||
-		    commit_locked_index(&index_lock))
-			die("unable to write new_index file");
+		if (0 <= fd) {
+			if (write_cache(fd, active_cache, active_nr) ||
+			    commit_locked_index(&index_lock))
+				die("unable to write new_index file");
+		}
 		commit_style = COMMIT_AS_IS;
 		return get_index_file();
 	}