Merge branch 'jc/pack-thin' into next

* jc/pack-thin:
  Use thin pack transfer in "git fetch".
  Add git-push --thin.

diff --cc upload-pack.c
index 3606529,3cdf428..635abb3
--- 1/upload-pack.c
--- 2/upload-pack.c
+++ b/upload-pack.c
@@@ -213,12 -218,9 +218,12 @@@ static int receive_needs(void
  
  static int send_ref(const char *refname, const unsigned char *sha1)
  {
-       static char *capabilities = "multi_ack";
+       static char *capabilities = "multi_ack thin-pack";
        struct object *o = parse_object(sha1);
  
 +      if (!o)
 +              die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
 +
        if (capabilities)
                packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
                        0, capabilities);