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

[Manuel Pégourié-Gonnard]

Le 21/05/2010 15:02, Khaled Hosny a écrit :
> On Fri, May 21, 2010 at 02:53:30PM +0200, Manuel Pégourié-Gonnard wrote:
>> IMHO, it shouldn't expect that. I tend to call that broken, unless someone
>> provides me with a good explanation.
> 
> There are some comments in the code, but basically Hans doesn't allocate
> attributes at TeX end, and in lua he reserves ranges for special uses.
> The code has a function, attributes.private, that allocates attributes
> in this range, but we override it sense it doesn't check if the
> attribute is already allocated, our replacement hand allocate attributes
> using \newluatexattribute.
> 
Ok, thanks for the 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.
> 
> I can work around it by allocating a dummy attribute first if you don't
> want to change it back, not a big deal.
> 
If allocating a single dummy attribute can solve the problem, I think is it the
way to go.

>> 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.
> 
> OK, I wanted to be on the safe side, but lets just assume there no other
> problems beyond the one we just found.
> 
Code assuming attributes don't start at 0 is probably fairly rare (all other
allocation starts at 0), so I think (hope) it'll be ok this way.

Thanks,
Manuel.