I'm suggesting that a HTML4 parser that has complex recovery code, and a mostly-copy-and-paste HTML5 parser that doesn't isn't a big win. Browsers are going to

I'm suggesting that a HTML4 parser that has complex recovery code, and a mostly-copy-and-paste HTML5 parser that doesn't isn't a big win. Browsers are going to have a complex, ugly, recovery-enabled parser in them either way, and the effort to add HTML5 to the recovery-enabled parser isn't very big, comparatively speaking.