effect of CSS first-letter and text-transform on languages without letter case

Hi,

(I don't write on these mailing lists often, so I apologize if it's not the
best place for this.)

Consider this CSS:

.cap::first-letter {
   text-transform: capitalize;
 }

Is its behavior defined for languages that don't have letter case?

I don't really see a clear definition in
https://www.w3.org/TR/css-text-3/#text-transform-property (is this is the
most relevant CSS version to check? Sorry if I'm not looking at the most
appropriate one).

Here's a simple example of how it works with Arabic text:
https://jsfiddle.net/amire80/0uzq39ja/

To me this is broken in both Chrome (63.0.3239.84) and Firefox (Nightly
59.0a1 (2017-12-24)) on macOS. I guess that in both engines the
first-letter property causes an unnecessary disconnection in the middle of
the word. It would be better if in Arabic this wouldn't do anything.

I can report rendering bugs in the browsers, but I feel that it makes more
sense to define it also in the standard.

(A sensible question is "why apply this to Arabic text in the first place".
The answer is that the same CSS can be used by a version of the same
content in several languages, and separating the CSS per alphabet is not a
trivial thing to scale. I came upon this when investigating this bug in
Wikipedia: https://phabricator.wikimedia.org/T183388 )

--
Amir Elisha Aharoni · אָמִיר אֱלִישָׁע אַהֲרוֹנִי
http://aharoni.wordpress.com
‪“We're living in pieces,
I want to live in peace.” – T. Moore‬