[XeTeX] longtable and RTL (Arabic)

[Arthur Reutenauer]

> I am really sorry, I forgot to attach the files! Here they are:

  And I'm sorry too, because I didn't notice your second message ;-)
Next time, if you could reply to yourself, that would make it easier to
follow the thread.

  Anyway, your problem is addressed at section 3.1 of the documentation:

	For typesetting RTL tables with longtable package, an
	experimental package, bidi-longtable package, is provided.
	bidi-longtable package should be loaded after longtable package.

  I suppose longtable posed special challenges that needed to be
addressed by a separate package.  And since bidi seems to protest when
you load longtable after itself, the order you should load the packages
seems to be:

	\usepackage{longtable}
	\usepackage{bidi}
	\usepackage{bidi-longtable}

> P.S.: Strange enough, the English words "Titel" and "Page" are set correctly LTR without defining a Latin language in the preamble.

  No, I'm guessing that's an artefact of how XeTeX works: back in the
times when it was using ICU, it would ship entire words to be shaped,
and then inserted back into the flow; and the shaping engine knows the
directionality of the different characters.  Presumably that same
behaviour has been retained with HarfBuzz; however I'll let Khaled
comment on that, as I haven't looked at the code.

	Arthur