[RFC] Remove additional spaces when quoting already-quoted lines

[Kurt Hackenberg]

On Sun, Jul 31, 2022 at 01:47:06PM -0400, Kurt Hackenberg wrote:

>I agree there should not be a space after the '>'.  The trouble is,
>that space is ambiguous: software can't tell whether it's part of the
>quoting or part of the original message.

I spoke too soon.  Now I've experimented with Mutt and Thunderbird[1]
and read some Mutt code, and have a better idea what's going on.  That
space in $indent_string confuses software less than I thought.

$indent_string is only used in a format=fixed reply; it's ignored for
format=flowed replies, which are required to use ">" (no space).  A
fixed block of quoted text with a space after '>' would cause trouble
if the message containing the quote is quoted in a flowed reply -- but
not much trouble.  Those quoted lines would be fixed -- would not end
with a space -- so would not be re-wrapped.  I think the code
constructing the quote in the flowed message would interpret that
space as space-stuffing, and delete it, but that's mostly harmless.

When no flowed-text message is involved, I don't think there's any
formal rule about space or no space, and text won't be re-wrapped or
modified.  A mail reader might misrepresent the quote levels and cause
confusion about who said what, but Thunderbird seems to understand it.
(Thunderbird replaces >>>... with multiple colored vertical lines,
and, in fixed text, accepts '>' with space as a quote marker.)


[1] Mutt and Thunderbird are the only mail readers I know of that
implement text/plain format=flowed.  Mutt only implements it
partially; it relies on an external editor to do some of it.
Thunderbird has its own editor.