Merge branch 'js/maint-graft-unhide-true-parents'

* js/maint-graft-unhide-true-parents:
  git repack: keep commits hidden by a graft
  Add a test showing that 'git repack' throws away grafted-away parents

Conflicts:
	git-repack.sh

environment.c

@@ -47,6 +47,7 @@ enum push_default_type push_default = PUSH_DEFAULT_MATCHING;
 #define OBJECT_CREATION_MODE OBJECT_CREATION_USES_HARDLINKS
 #endif
 enum object_creation_mode object_creation_mode = OBJECT_CREATION_MODE;
+int grafts_replace_parents = 1;
 
 /* Parallel index stat data preload? */
 int core_preload_index = 0;