LayoutTests/fast/repaint/body-innerhtml-quirks-mode.html

<script src="../../resources/ui-helper.js"></script>
<span>This text is inside an inline box.</span> This text should also disappear after clearing body innerHTML in quirks mode.
<script>
window.testRunner?.waitUntilDone();
window.testRunner?.dontForceRepaint();

async function runTest() {
    await UIHelper.renderingUpdate();
    document.body.innerHTML = "";
    await UIHelper.renderingUpdate();
    await UIHelper.renderingUpdate();
    window.testRunner?.notifyDone();
}

window.addEventListener('load', runTest);
</script>