[css3-text] text-autospace: ideograph-numeric|alpha exceptions

I was reviewing 'text-autospace' property[1] and figured out that we need some exceptional cases *not* to create 1/4em extra spacing.

If the numeric/non-ideographic letters match to one of the following criteria:
* fullwidth
* upright in vertical text flow using the 'text-orientation' property or the 'text-combine' property
* have different computed value of the 'writing-mode' property than the ideographic letters

If I'm missing other cases, or any other opinions, I'd appreciate to know.


[1] http://dev.w3.org/csswg/css3-text/#text-autospace


Regards,
Koji