style attr parsing surprise

CSS complained about "no values" for padding, and it turned out to be
something like

<element style="padding: 10px
15px">

Html_get_attr2() is removing the '\n' completely.

It turns out that we're doing the right thing (whereas I expected it
to be replaced by a ' ') because the style attr is %StyleSheet, which
is CDATA, and we are instructed to "Ignore line feeds" for CDATA.

But I'm writing this down anyway because it surprised me, and it's
good to save this away in the list archives (which may well have
a few variations on this already from years past).

(Or is it coming to be time to admit defeat for html4 and start
looking in the shocking endless immensity that is html5 when
it comes to such matters?)