This tests that typing a misspelling into a field that clears itself on keyup does not crash.
WebKit bug #<a href="https://bugs.webkit.org/show_bug.cgi?id=135044">135044</a>.

<br><br>

<input id="a" placeholder="Using iOS software keyboard, type 'abcdef' here" style="font-size: 25px; width: 100%;">

<script>
    document.getElementById("a").addEventListener("keyup", function() { this.value = ""; });
</script>