index-pack: skip collision check when not in repository

You can run "git index-pack path/to/foo.pack" outside of a
repository to generate an index file, or just to verify the
contents. There's no point in doing a collision check, since
we obviously do not have any objects to collide with.

The current code will blindly look in .git/objects based on
the result of setup_git_env(). That effectively gives us the
right answer (since we won't find any objects), but it's a
waste of time, and it conflicts with our desire to
eventually get rid of the "fallback to .git" behavior of
setup_git_env().

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index d450a6ada2a247fc316caada8820241fdf975e0f..f4b87c6c9f901e5834ce9e50db089fb487c6eafc 100644 (file)
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -787,13 +787,15 @@ static void sha1_object(const void *data, struct object_entry *obj_entry,
                        const unsigned char *sha1)
 {
        void *new_data = NULL;
-       int collision_test_needed;
+       int collision_test_needed = 0;
 
        assert(data || obj_entry);
 
-       read_lock();
-       collision_test_needed = has_sha1_file_with_flags(sha1, HAS_SHA1_QUICK);
-       read_unlock();
+       if (startup_info->have_repository) {
+               read_lock();
+               collision_test_needed = has_sha1_file_with_flags(sha1, HAS_SHA1_QUICK);
+               read_unlock();
+       }
 
        if (collision_test_needed && !data) {
                read_lock();