🚀 go-pugleaf

In Emacs 18.58, doing

  emacs -q
  C-x i somenonemptyfile RET
  C-x u

leaves the buffer (*scratch*) marked as modified, although it does
undo the insert.  The emacs Undo info node describes:


info>    If you notice that a buffer has been modified accidentally, the
info> easiest way to recover is to type `C-_' repeatedly until the stars
info> disappear from the front of the mode line.  At this time, all the
info> modifications you made have been cancelled.  If you do not remember
info> whether you changed the buffer deliberately, type `C-_' once, and when
info> you see the last change you made undone, you will remember why you
info> made it.  If it was an accident, leave it undone.  If it was
info> deliberate, redo the change as described in the preceding paragraph.

undo-threshold
90000
undo-high-threshold
100000

which is much greater than the files being inserted.

-Jerry