bug#2228: 23.0.90; rmail-cease-edit ignores changes to the message headers

[Richard M Stallman]

    > As it is now, you get the choice.  If you display the full headers and
    > then edit, then you get to edit the full headers.

    With the minor drawback that it doesn't actually work, hence this bug 
report.

It works fine for the usual job, editing the message body.
Making it work for editing headers probably takes 200 lines of code.

    rmailedit as a whole seems overly complex to me. If I were doing it,
    I'd copy the expanded message text to a new buffer for editing, rather
    than re-using the rmail buffer. Aborting an edit would just kill the
    buffer. Saving an edit would compare the buffer text with the region
    between msgbeg and msgend in rmail-view-buffer, and swap it in if it
    differed, then call rmail-show-message.

I would not object to switching to that approach, but still it shouldn't
normally show all the unpruned headers.