pack-objects: use --objects-edge-aggressive for shallow repos

When fetching into or pushing from a shallow repository, we want to
aggressively mark edges as uninteresting, since this decreases the pack
size.  However, aggressively marking edges can negatively affect
performance on large non-shallow repositories with lots of refs.

Teach pack-objects a --shallow option to indicate that we're pushing
from or fetching into a shallow repository.  Use
--objects-edge-aggressive only for shallow repositories and otherwise
use --objects-edge, which performs better in the general case.  Update
the callers to pass the --shallow option when they are dealing with a
shallow repository.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/Documentation/rev-list-options.txt b/Documentation/rev-list-options.txt
index 8cb6f92e19..2984f407a9 100644
--- a/Documentation/rev-list-options.txt
+++ b/Documentation/rev-list-options.txt
@@ -659,7 +659,8 @@ These options are mostly targeted for packing of Git repositories.
 
 --objects-edge-aggressive::
 	Similar to `--objects-edge`, but it tries harder to find excluded
-	commits at the cost of increased time.
+	commits at the cost of increased time.  This is used instead of
+	`--objects-edge` to build ``thin'' packs for shallow repositories.
 
 --unpacked::
 	Only useful with `--objects`; print the object IDs that are not