[luatex] Glue node without spec field?

[luigi scarso]

On Thu, Jan 7, 2010 at 1:10 PM, Taco Hoekwater <taco at elvenkind.com> wrote:
> luigi scarso wrote:
>>
>> If I understand it correctly,
>> if subtype is not 0 then spec is an empty node
>
> No, that is wrong. spec is *never* an empty node.
>
> The spec can be zero though, and that is a static spec with
> values 0pt plus 0pt minus 0pt. The lua interface treated that
> wrongly (all other node links cannot be zero, and there was
> no special case for spec fields).
>
> The non-zero subtype means that this glue matches
> one of the internal parameters, e.g. 9 == \rightskip,
> or that it is a leader (values 100-102).
Ah ok, now understand.

-- 
luigi