1 files changed, 163 insertions, 0 deletions
diff --git a/browser/components/sessionstore/test/browser_906076_lazy_tabs.js b/browser/components/sessionstore/test/browser_906076_lazy_tabs.js
new file mode 100644
index 0000000000..2fab82ca01
--- /dev/null
+++ b/browser/components/sessionstore/test/browser_906076_lazy_tabs.js
@@ -0,0 +1,163 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+const TEST_STATE = {
+  windows: [
+    {
+      tabs: [
+        {
+          entries: [{ url: "http://example.com", triggeringPrincipal_base64 }],
+        },
+        {
+          entries: [{ url: "http://example.com", triggeringPrincipal_base64 }],
+        },
+        {
+          entries: [{ url: "http://example.com", triggeringPrincipal_base64 }],
+        },
+        {
+          entries: [{ url: "http://example.com", triggeringPrincipal_base64 }],
+        },
+        {
+          entries: [{ url: "http://example.com", triggeringPrincipal_base64 }],
+        },
+        {
+          entries: [{ url: "http://example.com", triggeringPrincipal_base64 }],
+        },
+        {
+          entries: [{ url: "http://example.com", triggeringPrincipal_base64 }],
+        },
+        {
+          entries: [{ url: "http://example.com", triggeringPrincipal_base64 }],
+        },
+        {
+          entries: [{ url: "http://example.com", triggeringPrincipal_base64 }],
+        },
+        {
+          entries: [{ url: "http://example.com", triggeringPrincipal_base64 }],
+        },
+      ],
+    },
+  ],
+};
+
+const TEST_STATE_2 = {
+  windows: [
+    {
+      tabs: [
+        { entries: [{ url: "about:robots", triggeringPrincipal_base64 }] },
+        {
+          entries: [],
+          userTypedValue: "http://example.com",
+          userTypedClear: 1,
+        },
+      ],
+    },
+  ],
+};
+
+function countNonLazyTabs(win) {
+  win = win || window;
+  let count = 0;
+  for (let browser of win.gBrowser.browsers) {
+    if (browser.isConnected) {
+      count++;
+    }
+  }
+  return count;
+}
+
+/**
+ * Test that lazy browsers do not get prematurely inserted by
+ * code accessing browser bound properties on the unbound browser.
+ */
+
+add_task(async function test() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["browser.sessionstore.restore_on_demand", true],
+      ["browser.sessionstore.restore_tabs_lazily", true],
+    ],
+  });
+
+  let backupState = SessionStore.getBrowserState();
+
+  await promiseBrowserState(TEST_STATE);
+
+  info(
+    "Check that no lazy browsers get unnecessarily inserted after session restore"
+  );
+  is(countNonLazyTabs(), 1, "Window has only 1 non-lazy tab");
+
+  await TestUtils.topicObserved("sessionstore-state-write-complete");
+
+  // When sessionstore write occurs, tabs are checked for state changes.
+  // Make sure none of them insert their browsers when this happens.
+  info("Check that no lazy browsers get inserted after sessionstore write");
+  is(countNonLazyTabs(), 1, "Window has only 1 non-lazy tab");
+
+  info("Check that lazy browser gets inserted properly");
+  ok(
+    !gBrowser.browsers[1].isConnected,
+    "The browser that we're attempting to insert is indeed lazy"
+  );
+  gBrowser._insertBrowser(gBrowser.tabs[1]);
+  is(countNonLazyTabs(), 2, "Window now has 2 non-lazy tabs");
+
+  // Check if any lazy tabs got inserted when window closes.
+  let newWindow = await promiseNewWindowLoaded();
+
+  SessionStore.setWindowState(newWindow, JSON.stringify(TEST_STATE));
+
+  await new Promise(resolve => {
+    newWindow.addEventListener(
+      "unload",
+      () => {
+        info("Check that no lazy browsers get inserted when window closes");
+        is(countNonLazyTabs(newWindow), 1, "Window has only 1 non-lazy tab");
+
+        info(
+          "Check that it is not possible to insert a lazy browser after the window closed"
+        );
+        ok(
+          !newWindow.gBrowser.browsers[1].isConnected,
+          "The browser that we're attempting to insert is indeed lazy"
+        );
+        newWindow.gBrowser._insertBrowser(newWindow.gBrowser.tabs[1]);
+        is(
+          countNonLazyTabs(newWindow),
+          1,
+          "Window still has only 1 non-lazy tab"
+        );
+
+        resolve();
+      },
+      { once: true }
+    );
+
+    newWindow.close();
+  });
+
+  // Bug 1365933.
+  info(
+    "Check that session with tab having empty entries array gets restored properly"
+  );
+  await promiseBrowserState(TEST_STATE_2);
+
+  is(gBrowser.tabs.length, 2, "Window has 2 tabs");
+  is(
+    gBrowser.selectedBrowser.currentURI.spec,
+    "about:robots",
+    "Tab has the expected URL"
+  );
+
+  gBrowser.selectedTab = gBrowser.tabs[1];
+  await BrowserTestUtils.browserLoaded(gBrowser.selectedBrowser);
+  is(
+    gBrowser.selectedBrowser.currentURI.spec,
+    "http://example.com/",
+    "Tab has the expected URL"
+  );
+
+  // Cleanup.
+  await promiseBrowserState(backupState);
+});