1 files changed, 73 insertions, 0 deletions
diff --git a/dom/base/test/fullscreen/browser_fullscreen-window-open-race.js b/dom/base/test/fullscreen/browser_fullscreen-window-open-race.js
new file mode 100644
index 0000000000..4cf8a3d8c7
--- /dev/null
+++ b/dom/base/test/fullscreen/browser_fullscreen-window-open-race.js
@@ -0,0 +1,73 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+requestLongerTimeout(2);
+
+// Import helpers
+Services.scriptloader.loadSubScript(
+  "chrome://mochitests/content/browser/dom/base/test/fullscreen/fullscreen_helpers.js",
+  this
+);
+
+// This test tends to trigger a race in the fullscreen time telemetry,
+// where the fullscreen enter and fullscreen exit events (which use the
+// same histogram ID) overlap. That causes TelemetryStopwatch to log an
+// error, bug 1742890.
+SimpleTest.ignoreAllUncaughtExceptions(true);
+
+add_setup(async function () {
+  await pushPrefs(
+    ["full-screen-api.transition-duration.enter", "0 0"],
+    ["full-screen-api.transition-duration.leave", "0 0"],
+    ["full-screen-api.allow-trusted-requests-only", false]
+  );
+});
+
+add_task(async () => {
+  const url =
+    "http://mochi.test:8888/browser/dom/base/test/fullscreen/dummy_page.html";
+  const name = "foo";
+
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url,
+    },
+    async function (browser) {
+      info("open new window");
+      SpecialPowers.spawn(browser, [url, name], function (u, n) {
+        content.document.notifyUserGestureActivation();
+        content.window.open(u, n, "width=100,height=100");
+      });
+      let newWin = await BrowserTestUtils.waitForNewWindow({ url });
+      await SimpleTest.promiseFocus(newWin);
+
+      info("re-focusing main window");
+      await SimpleTest.promiseFocus(window);
+
+      info("open an existing window and request fullscreen");
+      await SpecialPowers.spawn(browser, [url, name], function (u, n) {
+        content.document.notifyUserGestureActivation();
+        content.window.open(u, n);
+        content.document.body.requestFullscreen();
+      });
+
+      // We call window.open() first than requestFullscreen() in a row on
+      // content page, but given that focus sync-up takes several IPC exchanges,
+      // so parent process ends up processing the requests in a reverse order,
+      // which should reject the fullscreen request and leave fullscreen.
+      await waitWidgetFullscreenEvent(window, false, true);
+
+      // Ensure the browser exits fullscreen state.
+      ok(!window.fullScreen, "The chrome window should not be in fullscreen");
+      ok(
+        !document.documentElement.hasAttribute("inDOMFullscreen"),
+        "The chrome document should not be in fullscreen"
+      );
+
+      await BrowserTestUtils.closeWindow(newWin);
+    }
+  );
+});