"use strict"; add_task(async function srcdoc_blocked_in_parent_process() { const iframe = document.createElement("iframe"); iframe.srcdoc = ""; document.documentElement.append(iframe); const iframe2 = document.createElement("iframe"); document.documentElement.append(iframe2); const load2Promise = BrowserTestUtils.waitForEvent(iframe2, "load", true); iframe2.src = "chrome://browser/content/aboutRobots.xhtml"; registerCleanupFunction(() => { iframe.remove(); iframe2.remove(); }); // We don't get load or error events for the srcdoc iframe, // so we assume it would finish loading before iframe2. await load2Promise; is( iframe.contentDocument.documentURI, "about:blank", "srcdoc frame should still be at about:blank" ); is( iframe.contentDocument.documentElement.innerHTML, "", "srcdoc markup should not have been parsed" ); });