bug#27525: 25.1; Line wrapping of bidi paragraphs

[Itai Berli]

I obviously didn't end up replacing the bullet points by numbers...

On Tue, Jul 4, 2017 at 12:10 PM, Itai Berli <itai.berli@gmail.com> wrote:

I'd like to add that this behavior breaks the Unicode bidirectional algorithm (UBA), and hence invalidates Emacs' claim of full conformance, or indeed of weak conformance, for that matter (so-called 'implicit bidirectionality' -- see section 4.2 of the UBA specifications).

The reason is that section 3.4 'Reordering Resolved Levels' of the algorithm states (I replaced the bullet points in the original by numbers):

> * The characters are shaped into glyphs [...]

> * The accumulated widths of those glyphs (in logical order) are used to determine line breaks.

The Emacs line-wrapping algorithm does not use the logical order of the glyphs to determine line breaks, as evidence by the example given in my original post, which I shall link to again: http://imgur.com/Bckn7zP