bug#2941: rmail's new handling of Babyl files is odd

[Richard M Stallman]

    >> C-u M-x rmail RET foo RET
    >> d
    >> x
    >> y
    >> C-x C-s
    >
    > Could you propose a patch that catches this case?

I can easily make this do whatever people generally want.
I did not want to change it for one vociferous person,
but I will gladly change to follow the general preference.