Made reading/writing undo info a bit more robust.
diff --git a/src/proto/undo.pro b/src/proto/undo.pro
index cea7d49..baa98c4 100644
--- a/src/proto/undo.pro
+++ b/src/proto/undo.pro
@@ -9,7 +9,7 @@
void u_compute_hash __ARGS((char_u *hash));
char_u *u_get_undo_file_name __ARGS((char_u *buf_ffname, int reading));
void u_write_undo __ARGS((char_u *name, int forceit, buf_T *buf, char_u *hash));
-void u_read_undo __ARGS((char_u *name, char_u *hash));
+void u_read_undo __ARGS((char_u *name, char_u *hash, char_u *orig_name));
void u_undo __ARGS((int count));
void u_redo __ARGS((int count));
void undo_time __ARGS((long step, int sec, int absolute));