[css-writing-modes-3] range limit for 'text-combine-upright: all' versus 'text-combine-upright: digits <integer>'

Koji, Elika,

"
all
     Attempt to typeset horizontally all consecutive characters within 
the box such that they take up the space of a single character within 
the vertical line box.

digits <integer>?

     Attempt to typeset horizontally each maximal sequence of consecutive 
ASCII digits (U+0030–U+0039) that has as many or fewer characters than 
the specified integer such that it takes up the space of a single 
character within the vertical line box. If the integer is omitted, it 
computes to 2. Integers outside the range 2-4 are invalid.
"
9.1 Horizontal-in-Vertical Composition: the text-combine-upright 
property
http://www.w3.org/TR/css-writing-modes-3/#text-combine-upright

There seems to be no implicit (and no explicit) range limit to the 
number of consecutive characters when using 'text-combine-upright: all' 
but there is a range 2-4 limit with 'text-combine-upright: digits n':
Q1: is that assumption correct? (To me, this seems odd and incoherent.)

Q2: If there is no range limitation with 'text-combine-upright: all', 
then
why should there be one with 'text-combine-upright: digits n' where 'n'
would be a [2-9] digit?

Q3: Is this test valid:

http://test.csswg.org/source/css-writing-modes-3/value-all-003.html

+CC: Masataka Yakura

Gérard

Received on Monday, 22 June 2015 00:42:17 UTC