1 files changed, 140 insertions, 0 deletions
diff --git a/browser/components/sessionstore/test/browser_636279.js b/browser/components/sessionstore/test/browser_636279.js
new file mode 100644
index 0000000000..ea116ee3f7
--- /dev/null
+++ b/browser/components/sessionstore/test/browser_636279.js
@@ -0,0 +1,140 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+var stateBackup = ss.getBrowserState();
+
+var statePinned = {
+  windows: [
+    {
+      tabs: [
+        {
+          entries: [
+            { url: "http://example.com#1", triggeringPrincipal_base64 },
+          ],
+          pinned: true,
+        },
+      ],
+    },
+  ],
+};
+
+var state = {
+  windows: [
+    {
+      tabs: [
+        {
+          entries: [
+            { url: "http://example.com#1", triggeringPrincipal_base64 },
+          ],
+        },
+        {
+          entries: [
+            { url: "http://example.com#2", triggeringPrincipal_base64 },
+          ],
+        },
+        {
+          entries: [
+            { url: "http://example.com#3", triggeringPrincipal_base64 },
+          ],
+        },
+        {
+          entries: [
+            { url: "http://example.com#4", triggeringPrincipal_base64 },
+          ],
+        },
+      ],
+    },
+  ],
+};
+
+function test() {
+  waitForExplicitFinish();
+
+  registerCleanupFunction(function () {
+    TabsProgressListener.uninit();
+    ss.setBrowserState(stateBackup);
+  });
+
+  TabsProgressListener.init();
+
+  window.addEventListener(
+    "SSWindowStateReady",
+    function () {
+      let firstProgress = true;
+
+      TabsProgressListener.setCallback(function (needsRestore, isRestoring) {
+        if (firstProgress) {
+          firstProgress = false;
+          is(isRestoring, 3, "restoring 3 tabs concurrently");
+        } else {
+          ok(isRestoring <= 3, "restoring max. 2 tabs concurrently");
+        }
+
+        if (0 == needsRestore) {
+          TabsProgressListener.unsetCallback();
+          waitForFocus(finish);
+        }
+      });
+
+      ss.setBrowserState(JSON.stringify(state));
+    },
+    { once: true }
+  );
+
+  ss.setBrowserState(JSON.stringify(statePinned));
+}
+
+function countTabs() {
+  let needsRestore = 0,
+    isRestoring = 0;
+  for (let window of Services.wm.getEnumerator("navigator:browser")) {
+    if (window.closed) {
+      continue;
+    }
+
+    for (let i = 0; i < window.gBrowser.tabs.length; i++) {
+      let browserState = ss.getInternalObjectState(
+        window.gBrowser.tabs[i].linkedBrowser
+      );
+      if (browserState == TAB_STATE_RESTORING) {
+        isRestoring++;
+      } else if (browserState == TAB_STATE_NEEDS_RESTORE) {
+        needsRestore++;
+      }
+    }
+  }
+
+  return [needsRestore, isRestoring];
+}
+
+var TabsProgressListener = {
+  init() {
+    Services.obs.addObserver(this, "sessionstore-debug-tab-restored");
+  },
+
+  uninit() {
+    Services.obs.removeObserver(this, "sessionstore-debug-tab-restored");
+    this.unsetCallback();
+  },
+
+  setCallback(callback) {
+    this.callback = callback;
+  },
+
+  unsetCallback() {
+    delete this.callback;
+  },
+
+  observe(browser, topic, data) {
+    TabsProgressListener.onRestored(browser);
+  },
+
+  onRestored(browser) {
+    if (
+      this.callback &&
+      ss.getInternalObjectState(browser) == TAB_STATE_RESTORING
+    ) {
+      this.callback.apply(null, countTabs());
+    }
+  },
+};