Rewrite mail CSS in place instead of cutting pieces out, so a strip can no
longer join text into a closing </style>, and escape < last. Decode escaped
letters before checking, parse url() properly and drop CSS that cannot be
parsed, and disable @import and image-set() in every spelling. The body
element's style goes through the same path.
Give <area> links the same target, rel and click handling as <a>, strip
<style> blocks from HTML quoted into the composer, and contain the editor's
layout as .message-body already is.
jcoffey-dev
55fcbf72f5