[css3-selectors] inheriting ::selection pseudo style

Section 7.3. The ::selection pseudo-element

The sections about the pseudo-elements ::first-letter and ::first-line explain 
in detail how they are inherited. Unfortunately this part is skipped in 
the ::selection part. 
Especially interesting is if child styles can overrule parent ::selection 
style (and also if ::first-letter or ::first-line can overrule ::selection 
styles).

So is it:
<div>
<span>This text has part of it 
<div::selection><span::selection>selected</div::selection></span::selection>
</span>
</div>

Or does it like ::first-line "split" the children:

<div>
<span>This text has part of it</span>
<div::selection><span><span::selection>selected</span::selection></span></div::selection>
<div>

In a way the later seems more natural, just really hard to write with 
pseudo-markup.

Regards
`Allan