Restore extension tab after reload

Work-around for https://crbug.com/511670
silentsakky · Aug 14, 2015 · 4ac8863 · 4ac8863
1 parent cf1d398
commit 4ac8863
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diff --git a/extensions/chromium/extension-router.js b/extensions/chromium/extension-router.js
@@ -83,6 +83,7 @@ limitations under the License.
 
   // When session restore is used, viewer pages may be loaded before the
   // webRequest event listener is attached (= page not found).
+  // Or the extension could have been crashed (OOM), leaving a sad tab behind.
   // Reload these tabs.
   chrome.tabs.query({
     url: CRX_BASE_URL + '*:*'
@@ -92,4 +93,25 @@ limitations under the License.
     }
   });
   console.log('Set up extension URL router.');
+
+  Object.keys(localStorage).forEach(function(key) {
+    // The localStorage item is set upon unload by chromecom.js.
+    var parsedKey = /^unload-(\d+)-(true|false)-(.+)/.exec(key);
+    if (parsedKey) {
+      var timeStart = parseInt(parsedKey[1], 10);
+      var isHidden = parsedKey[2] === 'true';
+      var url = parsedKey[3];
+      if (Date.now() - timeStart < 3000) {
+        // Is it a new item (younger than 3 seconds)? Assume that the extension
+        // just reloaded, so restore the tab (work-around for crbug.com/511670).
+        chrome.tabs.create({
+          url: chrome.runtime.getURL('restoretab.html') +
+            '?' + encodeURIComponent(url) +
+            '#' + encodeURIComponent(localStorage.getItem(key)),
+          active: !isHidden
+        });
+      }
+      localStorage.removeItem(key);
+    }
+  });
 })();
diff --git a/extensions/chromium/restoretab.html b/extensions/chromium/restoretab.html
@@ -0,0 +1,17 @@
+<!doctype html>
+<!--
+Copyright 2015 Mozilla Foundation
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+-->
+<script src="restoretab.js"></script>
diff --git a/extensions/chromium/restoretab.js b/extensions/chromium/restoretab.js
@@ -0,0 +1,33 @@
+/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
+/*
+Copyright 2015 Mozilla Foundation
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+/**
+ * This is part of the work-around for crbug.com/511670.
+ * - chromecom.js sets the URL and history state upon unload.
+ * - extension-router.js retrieves the saved state and opens restoretab.html
+ * - restoretab.html (this script) restores the URL and history state.
+ */
+'use strict';
+
+var url = decodeURIComponent(location.search.slice(1));
+var historyState = decodeURIComponent(location.hash.slice(1));
+
+historyState = historyState === 'undefined' ? null : JSON.parse(historyState);
+
+history.replaceState(historyState, null, url);
+location.reload();
diff --git a/web/chromecom.js b/web/chromecom.js
@@ -215,6 +215,23 @@ var ChromeCom = (function ChromeComClosure() {
     });
   }
 
+  if (window === top) {
+    // Chrome closes all extension tabs (crbug.com/511670) when the extension
+    // reloads. To counter this, the tab URL and history state is saved to
+    // localStorage and restored by extension-router.js.
+    // Unfortunately, the window and tab index are not restored. And if it was
+    // the only tab in an incognito window, then the tab is not restored either.
+    addEventListener('unload', function() {
+      // If the runtime is still available, the unload is most likely a normal
+      // tab closure. Otherwise it is most likely an extension reload.
+      if (!isRuntimeAvailable()) {
+        localStorage.setItem(
+          'unload-' + Date.now() + '-' + document.hidden + '-' + location.href,
+          JSON.stringify(history.state));
+      }
+    });
+  }
+
   // This port is used for several purposes:
   // 1. When disconnected, the background page knows that the frame has unload.
   // 2. When the referrer was saved in history.state.chromecomState, it is sent