Merge branch 'ds/push-sparse-tree-walk'

"git pack-objects" learned another algorithm to compute the set of
objects to send, that trades the resulting packfile off to save
traversal cost to favor small pushes.

* ds/push-sparse-tree-walk:
  pack-objects: create GIT_TEST_PACK_SPARSE
  pack-objects: create pack.useSparse setting
  revision: implement sparse algorithm
  list-objects: consume sparse tree walk
  revision: add mark_tree_uninteresting_sparse

builtin/rev-list.c

@@ -546,7 +546,7 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
 	if (prepare_revision_walk(&revs))
 		die("revision walk setup failed");
 	if (revs.tree_objects)
-		mark_edges_uninteresting(&revs, show_edge);
+		mark_edges_uninteresting(&revs, show_edge, 0);
 
 	if (bisect_list) {
 		int reaches, all;