Re: Message Mode and bidi

[Eli Zaretskii <eliz@gnu.org>]

> From: Joost Kremers <joostkremers@fastmail.fm>
> Cc: Eli Zaretskii <eliz@gnu.org>, emacs-devel@gnu.org
> Date: Mon, 19 Feb 2024 22:50:50 +0100
> 
> On Mon, Feb 19 2024, Christopher Culver via "Emacs development discussions." wrote:
> > Eli Zaretskii <eliz@gnu.org> writes:
> >> I cannot reproduce this.  What I see is that Message mode supports
> >> bidirectional text as expected, including what you describe in the
> >> previous paragraph regarding right-aligning the RTL text.  So please
> >> tell more what you did by describing in detail the commands you typed.
> >
> > I have tried this with a completely virgin Emacs installation, but
> > Message Mode continues to show less than full support for bidi text.
> 
> When you compose a new message, is there a line "--text follows this line--"
> separating the headers and the message text? In my case, there is (I use mu4e)
> and when I type Arabic text on the line below this text, I get the effect you
> mention. If I leave an empty line after "--text follows this line--", bidi works
> as expected.

Right.

> I believe this is due to the interaction of two things: 1. Emacs uses the first
> word of a paragraph to determine whether the paragraph is ltr or rtl; and 2.
> Emacs assumes that a paragraph is preceded by an empty line. So if you type rtl
> text on the line below the "--text follows this line--" separator, Emacs
> assumes the separator and the text you're typing belong to the same paragraph,
> and since the first word of this paragraph is from an ltr writing system, the
> paragraph is displayed ltr.

Exactly.