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.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin-commit.c b/builtin-commit.c
index 33aa593c21b70cd29a54e7b8151d78e092cfad3a..83b7c353ed6e4ca99a9bfae041c41280d31122a7 100644 (file)
--- 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();
        }