On Mon, Sep 05, 2022 at 07:40:54PM +1000, Cameron Simpson wrote:
It seems a little conceptually cleaner to have the editor do the
whole job, rather than divide it between the editor and Mutt. But
another complication is that you can edit a message more than once...
I think space stuffing is effectively an escape mechanism, like quoted
printable; not something you see at authoring time. The RFC even says
"(Note that space-stuffing is conceptually similar to dot-stuffing as
specified in [SMTP].)", which is again a transport level escaping.
So we need the overt trailing-space stuff because that's an indicator
of end-of-paragraph in f=f, but not the space stuffing, because that
is only needed to transport the text.
Space-stuffing doesn't have to be shown to the user while editing, but
it's part of format=flowed, and it's required, not optional. The
paragraph before the one you quoted is this:
On generation, any unquoted lines which start with ">", and any lines
which start with a space or "From " MUST be space-stuffed. Other
lines MAY be space-stuffed as desired.
<https://www.rfc-editor.org/rfc/rfc3676.html#section-4.4>
