problem with combining diacritcs in HTML5

I have a web page that writes into an HTML5 textarea via the javascript dom
interface. U+0332 COMBINING LOW LINE is incorrectly rendered as a spacing
low line in both Mozilla Firefox and Google Chrome, which is peculiar since
they use different rendering agents. Characters with a combining low line
encoded as a single Unicode codepoint are rendered correctly. Thus 's'
followed by U+0332 is rendered as 's' followed by a low line, but U+1E95
LATIN SMALL LETTER Z WITH LINE BELOW is correctly rendered with the
underscore beneath the 'z'. Is this a bug that happens to appear in two
different rendering agents? Incomplete Unicode support in the HTML5 spec?
Received on Sun Oct 07 2012 - 00:45:01 CDT