1 files changed, 110 insertions, 0 deletions
diff --git a/docshell/test/navigation/test_bug1699721.html b/docshell/test/navigation/test_bug1699721.html
new file mode 100644
index 0000000000..687c5306cf
--- /dev/null
+++ b/docshell/test/navigation/test_bug1699721.html
@@ -0,0 +1,110 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <script src="/tests/SimpleTest/SimpleTest.js"></script>
+    <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+<body>
+<pre id="test">
+<script type="text/javascript">
+  add_task(async function() {
+    let popup = window.open("blank.html");
+
+    info("opened popup");
+    await new Promise(resolve => {
+      popup.addEventListener("load", resolve, { once: true });
+    });
+
+    info("popup blank.html loaded");
+    let tell_opener = new URL("file_tell_opener.html", location.href);
+    // eslint-disable-next-line @microsoft/sdl/no-insecure-url
+    let xorigin_url = new URL(tell_opener.pathname, "http://example.com");
+
+    let resolveStartedUnload;
+    let startedUnload = new Promise(resolve => {
+      resolveStartedUnload = resolve;
+    });
+    let didFinishUnload = false;
+
+    let finishUnload = false;
+    popup.addEventListener("unload", function() {
+      resolveStartedUnload();
+      try {
+        // Spin a nested event loop in unload until we set `finishUnload`.
+        SpecialPowers.Services.tm.spinEventLoopUntil(
+          "Test(test_switch_back_nested.html)", () => finishUnload);
+      } finally {
+        info("exiting from unload nested event loop...");
+        didFinishUnload = true;
+      }
+    });
+
+    info("wait for message from popup");
+    let messagePromise = new Promise(resolve => {
+      addEventListener("message", evt => {
+        resolve();
+      }, { once: true });
+    });
+    popup.location = xorigin_url.href;
+    await messagePromise;
+
+    info("popup loaded, ensuring we're in unload");
+    await startedUnload;
+    is(didFinishUnload, false, "unload shouldn't have finished");
+
+    let switchStarted = SpecialPowers.spawnChrome([], async () => {
+      await new Promise(resolve => {
+        async function observer(subject, topic) {
+          is(topic, "http-on-examine-response");
+
+          let uri = subject.QueryInterface(Ci.nsIChannel).URI;
+          if (!uri.filePath.endsWith("file_tell_opener.html")) {
+            return;
+          }
+
+          Services.obs.removeObserver(observer, "http-on-examine-response");
+
+          // spin the event loop a few times to ensure we resolve after the process switch
+          for (let i = 0; i < 10; ++i) {
+            await new Promise(res => Services.tm.dispatchToMainThread(res));
+          }
+
+          info("resolving!");
+          resolve();
+        }
+        Services.obs.addObserver(observer, "http-on-examine-response");
+      });
+    });
+
+    info("Navigating back to the current process");
+    await SpecialPowers.spawn(popup, [tell_opener.href], (href) => {
+      content.location.href = href;
+    });
+
+    let messagePromise2 = new Promise(resolve => {
+      addEventListener("message", evt => {
+        resolve();
+      }, { once: true });
+    });
+
+    info("Waiting for the process switch to start");
+    await switchStarted;
+
+    // Finish unloading, and wait for the unload to complete
+    is(didFinishUnload, false, "unload shouldn't be finished");
+    finishUnload = true;
+    await new Promise(resolve => setTimeout(resolve, 0));
+    is(didFinishUnload, true, "unload should be finished");
+
+    info("waiting for navigation to complete");
+    await messagePromise2;
+
+    info("closing popup");
+    popup.close();
+
+    ok(true, "Didn't crash");
+  });
+</script>
+</pre>
+</body>
+</html>