1 files changed, 81 insertions, 0 deletions
diff --git a/browser/base/content/test/tabs/browser_relatedTabs_reset.js b/browser/base/content/test/tabs/browser_relatedTabs_reset.js
new file mode 100644
index 0000000000..531a9e723d
--- /dev/null
+++ b/browser/base/content/test/tabs/browser_relatedTabs_reset.js
@@ -0,0 +1,81 @@
+/* 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 () {
+  is(gBrowser.tabs.length, 1, "one tab is open initially");
+
+  const TestPage =
+    "http://mochi.test:8888/browser/browser/base/content/test/general/dummy_page.html";
+
+  // Add several new tabs in sequence
+  let tabs = [];
+  let ReferrerInfo = Components.Constructor(
+    "@mozilla.org/referrer-info;1",
+    "nsIReferrerInfo",
+    "init"
+  );
+
+  function getPrincipal(url, attrs) {
+    let uri = Services.io.newURI(url);
+    if (!attrs) {
+      attrs = {};
+    }
+    return Services.scriptSecurityManager.createContentPrincipal(uri, attrs);
+  }
+
+  function addTab(aURL, aReferrer) {
+    let referrerInfo = new ReferrerInfo(
+      Ci.nsIReferrerInfo.EMPTY,
+      true,
+      aReferrer
+    );
+    let triggeringPrincipal = getPrincipal(aURL);
+    let tab = BrowserTestUtils.addTab(gBrowser, aURL, {
+      referrerInfo,
+      triggeringPrincipal,
+    });
+    tabs.push(tab);
+    return BrowserTestUtils.browserLoaded(tab.linkedBrowser);
+  }
+
+  function loadTab(tab, url) {
+    let loaded = BrowserTestUtils.browserLoaded(tab.linkedBrowser);
+    info("Loading page: " + url);
+    BrowserTestUtils.loadURIString(tab.linkedBrowser, url);
+    return loaded;
+  }
+
+  function testPosition(tabNum, expectedPosition, msg) {
+    is(
+      Array.prototype.indexOf.call(gBrowser.tabs, tabs[tabNum]),
+      expectedPosition,
+      msg
+    );
+  }
+
+  // Initial selected tab
+  await addTab("http://mochi.test:8888/#0");
+  testPosition(0, 1, "Initial tab opened in position 1");
+  gBrowser.selectedTab = tabs[0];
+
+  // Related tabs
+  await addTab("http://mochi.test:8888/#1", gBrowser.currentURI);
+  testPosition(1, 2, "Related tab was opened to the far right");
+
+  await addTab("http://mochi.test:8888/#2", gBrowser.currentURI);
+  testPosition(2, 3, "Related tab was opened to the far right");
+
+  // Load a new page
+  await loadTab(tabs[0], TestPage);
+
+  // Add a new related tab after the page load
+  await addTab("http://mochi.test:8888/#3", gBrowser.currentURI);
+  testPosition(
+    3,
+    2,
+    "Tab opened to the right of initial tab after system navigation"
+  );
+
+  tabs.forEach(gBrowser.removeTab, gBrowser);
+});