Re: buffer is modified after commit

[martin rudalics]

> 3 - buffer-modified-p is incorrectly forcefully set to nil by the
>     special undo entries added in highlight-changes-rotate-faces.
>     That's correct if the buffer was not modified before undoing
>     this command, but is dangerous otherwise (will mark your buffer as
>     unmodified even though you haven't saved the changes).

Yes, that part is tricky and should be solved by a generic primitive
rather than my ad-hoc fix.  I thought that when the buffer is unmodified
at the time I do "this command", doing/undoing "this command" and
setting the modified status to nil should not cause any harm.  Can you
provide a counterexample?