[XeTeX] Bug or design flaw in Polyglossia 2012/04/29 v1.2.1

[Ian-Mathew Hornburg]

2013/3/30 Arthur Reutenauer <arthur.reutenauer at normalesup.org>:
> On Sat, Mar 30, 2013 at 08:49:57PM +0100, Peter Dyballa wrote:
>> When the missing characters are obviously Latin, why aren't they
>> taken from a Latin script, from \englishfont for example?

I use the Rachana font as well, and while the font contains Latin
letters for A-Z/a-z (and only those; no more), it may be programmed in
such a way that those glyphs aren’t accessible when passing the [mlym]
script tag.

I don’t believe this a bug. Font’s just not designed to be used with
Latin Script.