lockfile: add accessor get_lock_file_path()

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/commit.c b/builtin/commit.c
index 254477f..96aee0c 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -324,6 +324,7 @@
 	struct string_list partial;
 	struct pathspec pathspec;
 	int refresh_flags = REFRESH_QUIET;
+	const char *ret;
 
 	if (is_status)
 		refresh_flags |= REFRESH_UNMERGED;
@@ -344,7 +345,7 @@
 			die(_("unable to create temporary index"));
 
 		old_index_env = getenv(INDEX_ENVIRONMENT);
-		setenv(INDEX_ENVIRONMENT, index_lock.filename.buf, 1);
+		setenv(INDEX_ENVIRONMENT, get_lock_file_path(&index_lock), 1);
 
 		if (interactive_add(argc, argv, prefix, patch_interactive) != 0)
 			die(_("interactive add failed"));
@@ -355,7 +356,7 @@
 			unsetenv(INDEX_ENVIRONMENT);
 
 		discard_cache();
-		read_cache_from(index_lock.filename.buf);
+		read_cache_from(get_lock_file_path(&index_lock));
 		if (update_main_cache_tree(WRITE_TREE_SILENT) == 0) {
 			if (reopen_lock_file(&index_lock) < 0)
 				die(_("unable to write index file"));
@@ -365,7 +366,7 @@
 			warning(_("Failed to update main cache tree"));
 
 		commit_style = COMMIT_NORMAL;
-		return index_lock.filename.buf;
+		return get_lock_file_path(&index_lock);
 	}
 
 	/*
@@ -388,7 +389,7 @@
 		if (write_locked_index(&the_index, &index_lock, CLOSE_LOCK))
 			die(_("unable to write new_index file"));
 		commit_style = COMMIT_NORMAL;
-		return index_lock.filename.buf;
+		return get_lock_file_path(&index_lock);
 	}
 
 	/*
@@ -475,9 +476,9 @@
 		die(_("unable to write temporary index file"));
 
 	discard_cache();
-	read_cache_from(false_lock.filename.buf);
-
-	return false_lock.filename.buf;
+	ret = get_lock_file_path(&false_lock);
+	read_cache_from(ret);
+	return ret;
 }
 
 static int run_status(FILE *fp, const char *index_file, const char *prefix, int nowarn,