Re: bidi-display-reordering is now non-nil by default

[Chong Yidong <cyd@stupidchicken.com>]

Eli Zaretskii <eliz@gnu.org> writes:

> Yes.  This issue has nothing to do with paragraph direction (and the
> Gnus summary buffer ought to set bidi-paragraph-direction to
> left-to-right anyway).  This issue is about reordering a line of text
> that is not really a contiguous text, but rather a series of separate
> fields.  Either each field needs to be reordered separately, which can
> be done by separating them with TABs, or we need to "fix" the default
> reordering (which assumes the whole line is a single piece of text) by
> inserting LRM characters in strategical places.

Thanks, I think I see.

Still, it seems better not to change Gnus to proactively insert LRM
characters, but leave it to those users who care to customize it as
necessary.  In the default value of gnus-summary-line-format,

  "%U%R%z%I%(%[%4L: %-23,23f%]%) %s\n"

the subject (%s) is followed by a newline.  If a user wants to change
this to include, say, the article number, that could be done via

  "%U%R%z%I%(%[%4L: %-23,23f%]%) %s\u200E%N\n"

This has the advantage of avoiding inserting the insertion of excess LRM
characters by default.  The disadvantage, of course, is that it requires
some extra knowledge from users, but we can handle this by adding a note
to the docstring.