Merge branch 'nd/fetch-into-shallow'

When there is no sufficient overlap between old and new history
during a fetch into a shallow repository, we unnecessarily sent
objects the sending side knows the receiving end has.

* nd/fetch-into-shallow:
Add testcase for needless objects during a shallow fetch
list-objects: mark more commits as edges in mark_edges_uninteresting
list-objects: reduce one argument in mark_edges_uninteresting
upload-pack: delegate rev walking in shallow fetch to pack-objects
shallow: add setup_temporary_shallow()
shallow: only add shallow graft points to new shallow file
move setup_alternate_shallow and write_shallow_commits to shallow.c

diff --cc builtin/pack-objects.c
Simple merge

diff --cc commit.h
Simple merge

diff --cc fetch-pack.c
index 094267fd80cdb09feec75c89aa2f4931f11e583d,28195ed78b281204850de9c5bfeee03fa29efd79..13b5b43bfa9092476d8715c005e06086b7343a54
--- 1/fetch-pack.c
--- 2/fetch-pack.c
+++ b/fetch-pack.c
@@@ -897,9 -845,7 +846,9 @@@ static struct ref *do_fetch_pack(struc
        if (args->stateless_rpc)
                packet_flush(fd[1]);
        if (args->depth > 0)
-               setup_alternate_shallow();
+               setup_alternate_shallow(&shallow_lock, &alternate_shallow_file);
 +      else
 +              alternate_shallow_file = NULL;
        if (get_pack(args, fd, pack_lockfile))
                die("git fetch-pack: fetch failed.");
  

diff --cc http-push.c
Simple merge

diff --cc list-objects.c
Simple merge

diff --cc t/t5500-fetch-pack.sh
Simple merge

diff --cc upload-pack.c
Simple merge