Add file save counter to undo information. Add undotree() function.
diff --git a/src/structs.h b/src/structs.h
index d792c78..36b0870 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -327,6 +327,7 @@
visualinfo_T uh_visual; /* Visual areas before undo/after redo */
#endif
time_t uh_time; /* timestamp when the change was made */
+ long_u uh_save_nr; /* counter for last time saved */
#ifdef U_DEBUG
int uh_magic; /* magic number to check allocation */
#endif
@@ -1371,7 +1372,8 @@
int b_u_synced; /* entry lists are synced */
long b_u_seq_last; /* last used undo sequence number */
long b_u_seq_cur; /* hu_seq of header below which we are now */
- time_t b_u_seq_time; /* uh_time of header below which we are now */
+ time_t b_u_time_cur; /* uh_time of header below which we are now */
+ long_u b_u_last_save_nr; /* counter for last file write */
/*
* variables for "U" command in undo.c