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

[Glenn Morris]

Richard M Stallman wrote:

>     It fixes the above sequence; however I can still go from Babyl to mbox
>     with no prompting by doing:
>
>     C-u M-x rmail RET foo RET
>     d
>     x
>     y
      C-x C-s
>
> I think that y is the answer to a prompt.

OK, yes, it is the "expunge deleted mail" prompt.

> It is a feature that rmail-expunge-confirm avoids prompting twice.

Really? At the very least, you have inconsistencies:

C-u M-x rmail RET foo RET
d
s

and

C-u M-x rmail RET foo RET
d
x
y
s             ; rather than C-x C-s

both prompt twice: separately about converting to mbox, then about
expunging messages. This seems entirely sensible to me.

> If it prompts you about whether to expunge at all, it doesn't
> prompt a second time about the change in format.

The "expunge deleted mail" prompt is something an Rmail user will have
seen many times, and will answer without expecting that in this one
particular instance there is a hidden second question about changing
the format of the Rmail file.

> Of course, this can be changed if people prefer.

The current behaviour doesn't make sense to me. (Probably the
rmail-modify-format call should just be in rmail-expunge rather than
in rmail-expunge-and-save.)

I should imagine that people who use Rmail, use it often. So anyone
using CVS will have already switched to mbox and will never encounter
this. People who wait for 23.1 will encounter it once only. Changing
it in 23.2 will be largely pointless.