[csswg-drafts] Issue: [css-text-3] Line breaking opportunities at the boundary of a white-space:pre inline element marked as i18n

r12a has just labeled an issue for https://github.com/w3c/csswg-drafts
 as "i18n":

== [css-text-3] Line breaking opportunities at the boundary of a 
white-space:pre inline element ==
Browsers differ in behavior when faced with the following, if the 
line-end would normally fall between お and か (i.e. at the boundary of 
the `span`):

`<p>あいうえお<span style="white-space:pre">か</span>きくけこ</p>`

Live example here: http://jsbin.com/bedumox/edit?html,css,output

Firefox and Edge (and presto) allow the break between お and か. Safari 
and Chrome don't. Language tagging and the switching the `word-break` 
property between `auto` and `break-all` does not make any difference.

I suspect the Firefox / Edge behavior is correct, and the the Chrome /
 Safari behavior is a side effect of a bug of theirs that suppresses 
break opportunities at element boundaries [1][2], but I did not manage
 to find a justification either way in the spec for the case I am 
discussing here.

[1] https://bugs.chromium.org/p/chromium/issues/detail?id=282134
[2] https://bugs.webkit.org/show_bug.cgi?id=158771

See https://github.com/w3c/csswg-drafts/issues/189