[lltx] [luatexbase] Change in the behaviour of \newluatexattribute ?

[Manuel Pégourié-Gonnard]

Le 21/05/2010 14:42, Khaled Hosny a écrit :
> After spending most of the day debugging why Arabic shaping is broken in
> the luaotfload, it turned out to be an attribute issue. The first
> allocated attribute by \newluatexattribute is 0 and ConTeXt code don't
> seem to like that, it specifically expects attributes used in luaotfload
> to be < 255 and > 127.
> 
IMHO, it shouldn't expect that. I tend to call that broken, unless someone
provides me with a good explanation.

> The problem didn't show before switch to luatexbase, so I expect there
> was some change in how \newluatexattribute allocates new attributes.

There was a minor change, I don't remember the details right now, but indeed
allocation didn't start at 0 previously for some reason. Since allocation should
be a black box, I didn't expect the change to be noticeable, that's why I didn't
announce it.

> Also, to avoid any other hidden surprises, is there a way for luaotfload
> to assign attributes in the aforementioned range in a way that works
> nicely with the attributes package?
> 
No. I can't see any nice way to to that. Well, if less than 127 attributes have
been allocated, you could allocate dummy attributes up to 127, then start
allocating your attributes. If more than 255 attributes have already been
allocated, there's nothing you can do.

Manuel.