Going forward in history does not trigger pageshow #39798
Description
a1.html
<script>
onpageshow = () => console.log('a1 pageshow! ' + location.href);
</script>
<a href="a2.html">a2</a>
<button onclick="history.forward()">forward</button>
<button onclick="history.back()">back</button>a2.html
<script>
onpageshow = () => console.log('a2 pageshow! ' + location.href);
</script>
<a href="a1.html">a1</a>
<button onclick="history.forward()">forward</button>
<button onclick="history.back()">back</button>./mach run http://localhost:8000/a1.html, then press the a2 link, then press back, then press forward.
Expected:
a1 pageshow http://localhost:8000/a1.html
a2 pageshow http://localhost:8000/a2html
a1 pageshow http://localhost:8000/a1.html
a2 pageshow http://localhost:8000/a2html
Actual:
a1 pageshow http://localhost:8000/a1.html
a2 pageshow http://localhost:8000/a2html
a1 pageshow http://localhost:8000/a1.html
Any further history traversals in any direction do not trigger pageshow events.