<!doctype html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<iframe id="i" src="/common/blank.html"></iframe>
<script>
promise_test(async t => {
let start_length = navigation.entries().length;
let start_index = navigation.currentEntry.index;
let start_history_length = history.length;
// Wait for after the load event so that the navigation doesn't get converted
// into a replace navigation.
await new Promise(resolve => window.onload = () => t.step_timeout(resolve, 0));
await i.contentWindow.navigation.navigate("#").finished;
assert_equals(i.contentWindow.navigation.entries().length, 2);
assert_equals(i.contentWindow.navigation.currentEntry.index, 1);
assert_equals(navigation.entries().length, start_length);
assert_equals(navigation.currentEntry.index, start_index);
assert_equals(history.length, start_history_length + 1);
i.remove();
assert_equals(navigation.entries().length, start_length);
assert_equals(navigation.currentEntry.index, start_index);
assert_equals(history.length, start_history_length + 1);
// back() here should do nothing. The iframe that would have navigated has
// been removed. No navigate event should be fired.
navigation.onnavigate = t.unreached_func("navigate must not fire");
navigation.oncurrententrychange = t.unreached_func("currententrychange must not fire");
history.back();
// Give time for the navigation to proceed.
await new Promise(resolve => t.step_timeout(resolve, 20));
}, "history.back() does not fire a navigate event when there's nothing to navigate");
</script>