bug#2137: 23.0.60; Saving Rmail buffer does not show the "Saving file ..." message

[Stefan Monnier]

> Why?  There's no need to autosave the buffer in which we show
> messages, and the buffer where the whole collection is held, if it's
> modified, will be autosaved by the usual machinery.  What am I
> missing?

The buffer where the `mbox' is held doesn't have a buffer-file-name
(the view buffer has buffer-file-name set instead, so without
write-region-annotate-functions, the autosave file contains the
currently shown message rather than a copy of the mbox).


        Stefan