commit: allow prepare_commit_graft to handle arbitrary repositories

Move the global variable 'commit_graft_prepared' into the object
pool and convert the function prepare_commit_graft to work
an arbitrary repositories.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

commit.c

@@ -196,19 +196,17 @@ static int read_graft_file(struct repository *r, const char *graft_file)
 	return 0;
 }
 
-#define prepare_commit_graft(r) prepare_commit_graft_##r()
+static void prepare_commit_graft(struct repository *r)
-static void prepare_commit_graft_the_repository(void)
 {
-	static int commit_graft_prepared;
 	char *graft_file;
 
-	if (commit_graft_prepared)
+	if (r->parsed_objects->commit_graft_prepared)
 		return;
-	graft_file = get_graft_file(the_repository);
+	graft_file = get_graft_file(r);
-	read_graft_file(the_repository, graft_file);
+	read_graft_file(r, graft_file);
 	/* make sure shallows are read */
-	is_repository_shallow(the_repository);
+	is_repository_shallow(r);
-	commit_graft_prepared = 1;
+	r->parsed_objects->commit_graft_prepared = 1;
 }
 
 struct commit_graft *lookup_commit_graft_the_repository(const struct object_id *oid)

object.h

@@ -20,6 +20,8 @@ struct parsed_object_pool {
 	int is_shallow;
 	struct stat_validity *shallow_stat;
 	char *alternate_shallow_file;
+
+	int commit_graft_prepared;
 };
 
 struct parsed_object_pool *parsed_object_pool_new(void);