Bug 1709346 - Part 2: Add test for cancelling a long-running load by removing its subframes, r=kmag

This seems to be the behaviour which was causing the failures with twitter embeds. Differential Revision: https://phabricator.services.mozilla.com/D115707
2021-06-03 16:59:32 +00:00 · 2021-06-03 16:59:32 +00:00 · f2ced4c9c9
--- a/dom/tests/browser/browser.ini
+++ b/dom/tests/browser/browser.ini
@ -145,3 +145,7 @@ support-files =
 support-files =
  page_bytecode_cache_asm_js.html
  page_bytecode_cache_asm_js.js
+[browser_bug1709346.js]
+support-files =
+  load_forever.sjs
+  file_empty_cross_site_frame.html
--- a/dom/tests/browser/browser_bug1709346.js
+++ b/dom/tests/browser/browser_bug1709346.js
@ -0,0 +1,48 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+add_task(async function remove_subframe_in_cross_site_frame() {
+  await BrowserTestUtils.withNewTab(
+    "http://mochi.test:8888/browser/dom/tests/browser/file_empty_cross_site_frame.html",
+    async browser => {
+      await TestUtils.waitForCondition(
+        () => !XULBrowserWindow.isBusy,
+        "browser is not busy after the tab finishes loading"
+      );
+
+      // Spawn into the cross-site subframe, and begin loading a slow network
+      // connection. We'll cancel the load before this navigation completes.
+      await SpecialPowers.spawn(
+        browser.browsingContext.children[0],
+        [],
+        async () => {
+          let frame = content.document.createElement("iframe");
+          frame.src = "load_forever.sjs";
+          content.document.body.appendChild(frame);
+
+          frame.addEventListener("load", function() {
+            ok(false, "load should not finish before the frame is removed");
+          });
+        }
+      );
+
+      is(
+        XULBrowserWindow.isBusy,
+        true,
+        "browser should be busy after the load starts"
+      );
+
+      // Remove the outer iframe, ending the load within this frame's subframe
+      // early.
+      await SpecialPowers.spawn(browser, [], async () => {
+        content.document.querySelector("iframe").remove();
+      });
+
+      await TestUtils.waitForCondition(
+        () => !XULBrowserWindow.isBusy,
+        "Browser should no longer be busy after the frame is removed"
+      );
+    }
+  );
+});
--- a/dom/tests/browser/file_empty_cross_site_frame.html
+++ b/dom/tests/browser/file_empty_cross_site_frame.html
@ -0,0 +1,2 @@
+<!doctype html>
+<iframe src="http://example.com/browser/dom/tests/browser/file_empty.html"></iframe>
--- a/dom/tests/browser/load_forever.sjs
+++ b/dom/tests/browser/load_forever.sjs
@ -0,0 +1,15 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+let gResponses = [];
+
+function handleRequest(request, response) {
+  response.seizePower();
+  response.write("HTTP/1.1 200 OK\r\n");
+  response.write("Content-Type: text/plain; charset=utf-8\r\n");
+  response.write("Cache-Control: no-cache, must-revalidate\r\n");
+  response.write("\r\n");
+
+  // Keep the response alive indefinitely.
+  gResponses.push(response);
+}