Hi Yutaka,
It would be useful in macros to be able to control the undo behavior in macros. If a macro makes multiple changes to the text in a buffer, the undo command works backward one change at a time. It would be useful to be able to say:
Set/mark undo state
Make multiple changes
Macro finishes
Then if we use the undo command, it would undo all changes back to the initial mark specified in the macro, instead of one change at a time.
Thanks!
Bill