gecko-dev/layout/forms/crashtests/1617753.html

<style>
    LEGEND, FORM {
        white-space: pre-wrap;
    }

    LEGEND {
        max-height: 0em;
    }

    FORM {
        column-width: 1px;
    }

    FIELDSET {
        column-width: 1em;
    }
</style>
<form id="htmlvar00005" class="class3">
    <fieldset>
        <legend>
            <!-- COMMENT -->