<!DOCTYPE html>

<style type="text/css">
    * { quotes: "A" "B" "C" "D"; }
    q:before {
        content: close-quote open-quote open-quote close-quote no-close-quote open-quote close-quote close-quote open-quote;
    }
</style>

<p>There should be no quotes when the depth of the quote is negative, and the depth
should restart from 0 next. Should see the same line printed twice.</p>

ACDABAB<br>
<q></q>