Square roots containing line breaks don't render properly
The example
<math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
<msqrt>
<mtext mathvariant="italic">aaaaa</mtext>
<mspace linebreak="newline"></mspace>
<mtext mathvariant="italic">b</mtext>
</msqrt>
</math>
doesn't render properly in any of the HTML-CSS, CHTML, or SVG output formats. (Each fails in a different way, but all three have the two lines centered, when they should be left-justified.)