Add Pale Moon

application/palemoon/components/sessionstore/DocumentUtils.jsm

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+/* 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/. */
+
+this.EXPORTED_SYMBOLS = [ "DocumentUtils" ];
+
+const Cu = Components.utils;
+const Ci = Components.interfaces;
+
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource:///modules/sessionstore/XPathGenerator.jsm");
+
+this.DocumentUtils = {
+  /**
+   * Obtain form data for a DOMDocument instance.
+   *
+   * The returned object has 2 keys, "id" and "xpath". Each key holds an object
+   * which further defines form data.
+   *
+   * The "id" object maps element IDs to values. The "xpath" object maps the
+   * XPath of an element to its value.
+   *
+   * @param  aDocument
+   *         DOMDocument instance to obtain form data for.
+   * @return object
+   *         Form data encoded in an object.
+   */
+  getFormData: function DocumentUtils_getFormData(aDocument) {
+    let formNodes = aDocument.evaluate(
+      XPathGenerator.restorableFormNodes,
+      aDocument,
+      XPathGenerator.resolveNS,
+      Ci.nsIDOMXPathResult.UNORDERED_NODE_ITERATOR_TYPE, null
+    );
+
+    let node;
+    let ret = {id: {}, xpath: {}};
+
+    // Limit the number of XPath expressions for performance reasons. See
+    // bug 477564.
+    const MAX_TRAVERSED_XPATHS = 100;
+    let generatedCount = 0;
+
+    while (node = formNodes.iterateNext()) {
+      let nId = node.id;
+      let hasDefaultValue = true;
+      let value;
+
+      // Only generate a limited number of XPath expressions for perf reasons
+      // (cf. bug 477564)
+      if (!nId && generatedCount > MAX_TRAVERSED_XPATHS) {
+        continue;
+      }
+
+      if (node instanceof Ci.nsIDOMHTMLInputElement ||
+          node instanceof Ci.nsIDOMHTMLTextAreaElement) {
+        switch (node.type) {
+          case "checkbox":
+          case "radio":
+            value = node.checked;
+            hasDefaultValue = value == node.defaultChecked;
+            break;
+          case "file":
+            value = { type: "file", fileList: node.mozGetFileNameArray() };
+            hasDefaultValue = !value.fileList.length;
+            break;
+          default: // text, textarea
+            value = node.value;
+            hasDefaultValue = value == node.defaultValue;
+            break;
+        }
+      } else if (!node.multiple) {
+        // <select>s without the multiple attribute are hard to determine the
+        // default value, so assume we don't have the default.
+        hasDefaultValue = false;
+        value = { selectedIndex: node.selectedIndex, value: node.value };
+      } else {
+        // <select>s with the multiple attribute are easier to determine the
+        // default value since each <option> has a defaultSelected
+        let options = Array.map(node.options, function(aOpt, aIx) {
+          let oSelected = aOpt.selected;
+          hasDefaultValue = hasDefaultValue && (oSelected == aOpt.defaultSelected);
+          return oSelected ? aOpt.value : -1;
+        });
+        value = options.filter(function(aIx) aIx !== -1);
+      }
+
+      // In order to reduce XPath generation (which is slow), we only save data
+      // for form fields that have been changed. (cf. bug 537289)
+      if (!hasDefaultValue) {
+        if (nId) {
+          ret.id[nId] = value;
+        } else {
+          generatedCount++;
+          ret.xpath[XPathGenerator.generate(node)] = value;
+        }
+      }
+    }
+
+    return ret;
+  },
+
+  /**
+   * Merges form data on a document from previously obtained data.
+   *
+   * This is the inverse of getFormData(). The data argument is the same object
+   * type which is returned by getFormData(): an object containing the keys
+   * "id" and "xpath" which are each objects mapping element identifiers to
+   * form values.
+   *
+   * Where the document has existing form data for an element, the value
+   * will be replaced. Where the document has a form element but no matching
+   * data in the passed object, the element is untouched.
+   *
+   * @param  aDocument
+   *         DOMDocument instance to which to restore form data.
+   * @param  aData
+   *         Object defining form data.
+   */
+  mergeFormData: function DocumentUtils_mergeFormData(aDocument, aData) {
+    if ("xpath" in aData) {
+      for each (let [xpath, value] in Iterator(aData.xpath)) {
+        let node = XPathGenerator.resolve(aDocument, xpath);
+
+        if (node) {
+          this.restoreFormValue(node, value, aDocument);
+        }
+      }
+    }
+
+    if ("id" in aData) {
+      for each (let [id, value] in Iterator(aData.id)) {
+        let node = aDocument.getElementById(id);
+
+        if (node) {
+          this.restoreFormValue(node, value, aDocument);
+        }
+      }
+    }
+  },
+
+  /**
+   * Low-level function to restore a form value to a DOMNode.
+   *
+   * If you want a higher-level interface, see mergeFormData().
+   *
+   * When the value is changed, the function will fire the appropriate DOM
+   * events.
+   *
+   * @param  aNode
+   *         DOMNode to set form value on.
+   * @param  aValue
+   *         Value to set form element to.
+   * @param  aDocument [optional]
+   *         DOMDocument node belongs to. If not defined, node.ownerDocument
+   *         is used.
+   */
+  restoreFormValue: function DocumentUtils_restoreFormValue(aNode, aValue, aDocument) {
+    aDocument = aDocument || aNode.ownerDocument;
+
+    let eventType;
+
+    if (typeof aValue == "string" && aNode.type != "file") {
+      // Don't dispatch an input event if there is no change.
+      if (aNode.value == aValue) {
+        return;
+      }
+
+      aNode.value = aValue;
+      eventType = "input";
+    } else if (typeof aValue == "boolean") {
+      // Don't dispatch a change event for no change.
+      if (aNode.checked == aValue) {
+        return;
+      }
+
+      aNode.checked = aValue;
+      eventType = "change";
+    } else if (typeof aValue == "number") {
+      // handle select backwards compatibility, example { "#id" : index }
+      // We saved the value blindly since selects take more work to determine
+      // default values. So now we should check to avoid unnecessary events.
+      if (aNode.selectedIndex == aValue) {
+        return;
+      }
+
+      if (aValue < aNode.options.length) {
+        aNode.selectedIndex = aValue;
+        eventType = "change";
+      }
+    } else if (aValue && aValue.selectedIndex >= 0 && aValue.value) {
+      // handle select new format
+
+      // Don't dispatch a change event for no change
+      if (aNode.options[aNode.selectedIndex].value == aValue.value) {
+        return;
+      }
+
+      // find first option with matching aValue if possible
+      for (let i = 0; i < aNode.options.length; i++) {
+        if (aNode.options[i].value == aValue.value) {
+          aNode.selectedIndex = i;
+          break;
+        }
+      }
+      eventType = "change";
+    } else if (aValue && aValue.fileList && aValue.type == "file" &&
+      aNode.type == "file") {
+      aNode.mozSetFileNameArray(aValue.fileList, aValue.fileList.length);
+      eventType = "input";
+    } else if (aValue && typeof aValue.indexOf == "function" && aNode.options) {
+      Array.forEach(aNode.options, function(opt, index) {
+        // don't worry about malformed options with same values
+        opt.selected = aValue.indexOf(opt.value) > -1;
+
+        // Only fire the event here if this wasn't selected by default
+        if (!opt.defaultSelected) {
+          eventType = "change";
+        }
+      });
+    }
+
+    // Fire events for this node if applicable
+    if (eventType) {
+      let event = aDocument.createEvent("UIEvents");
+      event.initUIEvent(eventType, true, true, aDocument.defaultView, 0);
+      aNode.dispatchEvent(event);
+    }
+  }
+};

application/palemoon/components/sessionstore/SessionStorage.jsm

@@ -0,0 +1,165 @@
+/* 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/. */
+
+this.EXPORTED_SYMBOLS = ["SessionStorage"];
+
+const Cu = Components.utils;
+
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+
+XPCOMUtils.defineLazyModuleGetter(this, "SessionStore",
+  "resource:///modules/sessionstore/SessionStore.jsm");
+
+this.SessionStorage = {
+  /**
+   * Updates all sessionStorage "super cookies"
+   * @param aDocShell
+   *        That tab's docshell (containing the sessionStorage)
+   * @param aFullData
+   *        always return privacy sensitive data (use with care)
+   */
+  serialize: function ssto_serialize(aDocShell, aFullData) {
+    return DomStorage.read(aDocShell, aFullData);
+  },
+
+  /**
+   * Restores all sessionStorage "super cookies".
+   * @param aDocShell
+   *        A tab's docshell (containing the sessionStorage)
+   * @param aStorageData
+   *        Storage data to be restored
+   */
+  deserialize: function ssto_deserialize(aDocShell, aStorageData) {
+    DomStorage.write(aDocShell, aStorageData);
+  }
+};
+
+Object.freeze(SessionStorage);
+
+let DomStorage = {
+  /**
+   * Reads all session storage data from the given docShell.
+   * @param aDocShell
+   *        A tab's docshell (containing the sessionStorage)
+   * @param aFullData
+   *        Always return privacy sensitive data (use with care)
+   */
+  read: function DomStorage_read(aDocShell, aFullData) {
+    let data = {};
+    let isPinned = aDocShell.isAppTab;
+    let shistory = aDocShell.sessionHistory;
+
+    for (let i = 0; i < shistory.count; i++) {
+      let principal = History.getPrincipalForEntry(shistory, i, aDocShell);
+      if (!principal)
+        continue;
+
+      // Check if we're allowed to store sessionStorage data.
+      let isHTTPS = principal.URI && principal.URI.schemeIs("https");
+      if (aFullData || SessionStore.checkPrivacyLevel(isHTTPS, isPinned)) {
+        let origin = principal.extendedOrigin;
+
+        // Don't read a host twice.
+        if (!(origin in data)) {
+          let originData = this._readEntry(principal, aDocShell);
+          if (Object.keys(originData).length) {
+            data[origin] = originData;
+          }
+        }
+      }
+    }
+
+    return data;
+  },
+
+  /**
+   * Writes session storage data to the given tab.
+   * @param aDocShell
+   *        A tab's docshell (containing the sessionStorage)
+   * @param aStorageData
+   *        Storage data to be restored
+   */
+  write: function DomStorage_write(aDocShell, aStorageData) {
+    for (let [host, data] in Iterator(aStorageData)) {
+      let uri = Services.io.newURI(host, null, null);
+      let principal = Services.scriptSecurityManager.getDocShellCodebasePrincipal(uri, aDocShell);
+      let storageManager = aDocShell.QueryInterface(Components.interfaces.nsIDOMStorageManager);
+      let window = aDocShell.QueryInterface(Components.interfaces.nsIInterfaceRequestor)
+                            .getInterface(Components.interfaces.nsIDOMWindow);
+
+      // There is no need to pass documentURI, it's only used to fill documentURI property of
+      // domstorage event, which in this case has no consumer.  Prevention of events in case
+      // of missing documentURI will be solved in a followup bug to bug 600307.
+      try {
+        let storage = storageManager.createStorage(window, principal, "", aDocShell.usePrivateBrowsing);
+      } catch(e) {
+        Cu.reportError(e);
+      }
+
+      for (let [key, value] in Iterator(data)) {
+        try {
+          storage.setItem(key, value);
+        } catch (e) {
+          // throws e.g. for URIs that can't have sessionStorage
+          Cu.reportError(e);
+        }
+      }
+    }
+  },
+
+  /**
+   * Reads an entry in the session storage data contained in a tab's history.
+   * @param aURI
+   *        That history entry uri
+   * @param aDocShell
+   *        A tab's docshell (containing the sessionStorage)
+   */
+  _readEntry: function DomStorage_readEntry(aPrincipal, aDocShell) {
+    let hostData = {};
+    let storage;
+
+    try {
+      let storageManager = aDocShell.QueryInterface(Components.interfaces.nsIDOMStorageManager);
+      storage = storageManager.getStorage(aPrincipal);
+    } catch (e) {
+      // sessionStorage might throw if it's turned off, see bug 458954
+    }
+
+    if (storage && storage.length) {
+       for (let i = 0; i < storage.length; i++) {
+        try {
+          let key = storage.key(i);
+          hostData[key] = storage.getItem(key);
+        } catch (e) {
+          // This currently throws for secured items (cf. bug 442048).
+        }
+      }
+    }
+
+    return hostData;
+  }
+};
+
+let History = {
+  /**
+   * Returns a given history entry's URI.
+   * @param aHistory
+   *        That tab's session history
+   * @param aIndex
+   *        The history entry's index
+   * @param aDocShell
+   *        That tab's docshell
+   */
+  getPrincipalForEntry: function History_getPrincipalForEntry(aHistory,
+                                                              aIndex,
+                                                              aDocShell) {
+    try {
+      return Services.scriptSecurityManager.getDocShellCodebasePrincipal(
+        aHistory.getEntryAtIndex(aIndex, false).URI, aDocShell);
+    } catch (e) {
+      // This might throw for some reason.
+    }
+  },
+};

application/palemoon/components/sessionstore/XPathGenerator.jsm

@@ -0,0 +1,97 @@
+/* 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/. */
+
+this.EXPORTED_SYMBOLS = ["XPathGenerator"];
+
+this.XPathGenerator = {
+  // these two hashes should be kept in sync
+  namespaceURIs:     { "xhtml": "http://www.w3.org/1999/xhtml" },
+  namespacePrefixes: { "http://www.w3.org/1999/xhtml": "xhtml" },
+
+  /**
+   * Generates an approximate XPath query to an (X)HTML node
+   */
+  generate: function sss_xph_generate(aNode) {
+    // have we reached the document node already?
+    if (!aNode.parentNode)
+      return "";
+
+    // Access localName, namespaceURI just once per node since it's expensive.
+    let nNamespaceURI = aNode.namespaceURI;
+    let nLocalName = aNode.localName;
+
+    let prefix = this.namespacePrefixes[nNamespaceURI] || null;
+    let tag = (prefix ? prefix + ":" : "") + this.escapeName(nLocalName);
+
+    // stop once we've found a tag with an ID
+    if (aNode.id)
+      return "//" + tag + "[@id=" + this.quoteArgument(aNode.id) + "]";
+
+    // count the number of previous sibling nodes of the same tag
+    // (and possible also the same name)
+    let count = 0;
+    let nName = aNode.name || null;
+    for (let n = aNode; (n = n.previousSibling); )
+      if (n.localName == nLocalName && n.namespaceURI == nNamespaceURI &&
+          (!nName || n.name == nName))
+        count++;
+
+    // recurse until hitting either the document node or an ID'd node
+    return this.generate(aNode.parentNode) + "/" + tag +
+           (nName ? "[@name=" + this.quoteArgument(nName) + "]" : "") +
+           (count ? "[" + (count + 1) + "]" : "");
+  },
+
+  /**
+   * Resolves an XPath query generated by XPathGenerator.generate
+   */
+  resolve: function sss_xph_resolve(aDocument, aQuery) {
+    let xptype = Components.interfaces.nsIDOMXPathResult.FIRST_ORDERED_NODE_TYPE;
+    return aDocument.evaluate(aQuery, aDocument, this.resolveNS, xptype, null).singleNodeValue;
+  },
+
+  /**
+   * Namespace resolver for the above XPath resolver
+   */
+  resolveNS: function sss_xph_resolveNS(aPrefix) {
+    return XPathGenerator.namespaceURIs[aPrefix] || null;
+  },
+
+  /**
+   * @returns valid XPath for the given node (usually just the local name itself)
+   */
+  escapeName: function sss_xph_escapeName(aName) {
+    // we can't just use the node's local name, if it contains
+    // special characters (cf. bug 485482)
+    return /^\w+$/.test(aName) ? aName :
+           "*[local-name()=" + this.quoteArgument(aName) + "]";
+  },
+
+  /**
+   * @returns a properly quoted string to insert into an XPath query
+   */
+  quoteArgument: function sss_xph_quoteArgument(aArg) {
+    return !/'/.test(aArg) ? "'" + aArg + "'" :
+           !/"/.test(aArg) ? '"' + aArg + '"' :
+           "concat('" + aArg.replace(/'+/g, "',\"$&\",'") + "')";
+  },
+
+  /**
+   * @returns an XPath query to all savable form field nodes
+   */
+  get restorableFormNodes() {
+    // for a comprehensive list of all available <INPUT> types see
+    // http://mxr.mozilla.org/mozilla-central/search?string=kInputTypeTable
+    let ignoreTypes = ["password", "hidden", "button", "image", "submit", "reset"];
+    // XXXzeniko work-around until lower-case has been implemented (bug 398389)
+    let toLowerCase = '"ABCDEFGHIJKLMNOPQRSTUVWXYZ", "abcdefghijklmnopqrstuvwxyz"';
+    let ignore = "not(translate(@type, " + toLowerCase + ")='" +
+      ignoreTypes.join("' or translate(@type, " + toLowerCase + ")='") + "')";
+    let formNodesXPath = "//textarea|//select|//xhtml:textarea|//xhtml:select|" +
+      "//input[" + ignore + "]|//xhtml:input[" + ignore + "]";
+
+    delete this.restorableFormNodes;
+    return (this.restorableFormNodes = formNodesXPath);
+  }
+};

application/palemoon/components/sessionstore/_SessionFile.jsm

@@ -0,0 +1,311 @@
+/* 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/. */
+
+"use strict";
+
+this.EXPORTED_SYMBOLS = ["_SessionFile"];
+
+/**
+ * Implementation of all the disk I/O required by the session store.
+ * This is a private API, meant to be used only by the session store.
+ * It will change. Do not use it for any other purpose.
+ *
+ * Note that this module implicitly depends on one of two things:
+ * 1. either the asynchronous file I/O system enqueues its requests
+ *   and never attempts to simultaneously execute two I/O requests on
+ *   the files used by this module from two distinct threads; or
+ * 2. the clients of this API are well-behaved and do not place
+ *   concurrent requests to the files used by this module.
+ *
+ * Otherwise, we could encounter bugs, especially under Windows,
+ *   e.g. if a request attempts to write sessionstore.js while
+ *   another attempts to copy that file.
+ *
+ * This implementation uses OS.File, which guarantees property 1.
+ */
+
+const Cu = Components.utils;
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/osfile.jsm");
+Cu.import("resource://gre/modules/Promise.jsm");
+
+XPCOMUtils.defineLazyModuleGetter(this, "NetUtil",
+  "resource://gre/modules/NetUtil.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "FileUtils",
+  "resource://gre/modules/FileUtils.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "Task",
+  "resource://gre/modules/Task.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "console",
+  "resource://gre/modules/devtools/Console.jsm");
+
+// An encoder to UTF-8.
+XPCOMUtils.defineLazyGetter(this, "gEncoder", function () {
+  return new TextEncoder();
+});
+// A decoder.
+XPCOMUtils.defineLazyGetter(this, "gDecoder", function () {
+  return new TextDecoder();
+});
+
+this._SessionFile = {
+  /**
+   * A promise fulfilled once initialization (either synchronous or
+   * asynchronous) is complete.
+   */
+  promiseInitialized: function SessionFile_initialized() {
+    return SessionFileInternal.promiseInitialized;
+  },
+  /**
+   * Read the contents of the session file, asynchronously.
+   */
+  read: function SessionFile_read() {
+    return SessionFileInternal.read();
+  },
+  /**
+   * Read the contents of the session file, synchronously.
+   */
+  syncRead: function SessionFile_syncRead() {
+    return SessionFileInternal.syncRead();
+  },
+  /**
+   * Write the contents of the session file, asynchronously.
+   */
+  write: function SessionFile_write(aData) {
+    return SessionFileInternal.write(aData);
+  },
+  /**
+   * Create a backup copy, asynchronously.
+   */
+  createBackupCopy: function SessionFile_createBackupCopy() {
+    return SessionFileInternal.createBackupCopy();
+  },
+  /**
+   * Wipe the contents of the session file, asynchronously.
+   */
+  wipe: function SessionFile_wipe() {
+    return SessionFileInternal.wipe();
+  }
+};
+
+Object.freeze(_SessionFile);
+
+/**
+ * Utilities for dealing with promises and Task.jsm
+ */
+const TaskUtils = {
+  /**
+   * Add logging to a promise.
+   *
+   * @param {Promise} promise
+   * @return {Promise} A promise behaving as |promise|, but with additional
+   * logging in case of uncaught error.
+   */
+  captureErrors: function captureErrors(promise) {
+    return promise.then(
+      null,
+      function onError(reason) {
+        console.error("Uncaught asynchronous error:", reason);
+        throw reason;
+      }
+    );
+  },
+  /**
+   * Spawn a new Task from a generator.
+   *
+   * This function behaves as |Task.spawn|, with the exception that it
+   * adds logging in case of uncaught error. For more information, see
+   * the documentation of |Task.jsm|.
+   *
+   * @param {generator} gen Some generator.
+   * @return {Promise} A promise built from |gen|, with the same semantics
+   * as |Task.spawn(gen)|.
+   */
+  spawn: function spawn(gen) {
+    return this.captureErrors(Task.spawn(gen));
+  }
+};
+
+let SessionFileInternal = {
+  /**
+   * A promise fulfilled once initialization is complete
+   */
+  promiseInitialized: Promise.defer(),
+
+  /**
+   * The path to sessionstore.js
+   */
+  path: OS.Path.join(OS.Constants.Path.profileDir, "sessionstore.js"),
+
+  /**
+   * The path to sessionstore.bak
+   */
+  backupPath: OS.Path.join(OS.Constants.Path.profileDir, "sessionstore.bak"),
+
+  /**
+   * Utility function to safely read a file synchronously.
+   * @param aPath
+   *        A path to read the file from.
+   * @returns string if successful, undefined otherwise.
+   */
+  readAuxSync: function ssfi_readAuxSync(aPath) {
+    let text;
+    try {
+      let file = new FileUtils.File(aPath);
+      let chan = NetUtil.newChannel(file);
+      let stream = chan.open();
+      text = NetUtil.readInputStreamToString(stream, stream.available(),
+        {charset: "utf-8"});
+    } catch (e if e.result == Components.results.NS_ERROR_FILE_NOT_FOUND) {
+      // Ignore exceptions about non-existent files.
+    } catch (ex) {
+      // Any other error.
+      console.error("Uncaught error:", ex);
+    } finally {
+      return text;
+    }
+  },
+
+  /**
+   * Read the sessionstore file synchronously.
+   *
+   * This function is meant to serve as a fallback in case of race
+   * between a synchronous usage of the API and asynchronous
+   * initialization.
+   *
+   * In case if sessionstore.js file does not exist or is corrupted (something
+   * happened between backup and write), attempt to read the sessionstore.bak
+   * instead.
+   */
+  syncRead: function ssfi_syncRead() {
+    // First read the sessionstore.js.
+    let text = this.readAuxSync(this.path);
+    if (typeof text === "undefined") {
+      // If sessionstore.js does not exist or is corrupted, read sessionstore.bak.
+      text = this.readAuxSync(this.backupPath);
+    }
+    return text || "";
+  },
+
+  /**
+   * Utility function to safely read a file asynchronously.
+   * @param aPath
+   *        A path to read the file from.
+   * @param aReadOptions
+   *        Read operation options.
+   *        |outExecutionDuration| option will be reused and can be
+   *        incrementally updated by the worker process.
+   * @returns string if successful, undefined otherwise.
+   */
+  readAux: function ssfi_readAux(aPath, aReadOptions) {
+    let self = this;
+    return TaskUtils.spawn(function () {
+      let text;
+      try {
+        let bytes = yield OS.File.read(aPath, undefined, aReadOptions);
+        text = gDecoder.decode(bytes);
+      } catch (ex if self._isNoSuchFile(ex)) {
+        // Ignore exceptions about non-existent files.
+      } catch (ex) {
+        // Any other error.
+        console.error("Uncaught error - with the file: " + self.path, ex);
+      }
+      throw new Task.Result(text);
+    });
+  },
+
+  /**
+   * Read the sessionstore file asynchronously.
+   *
+   * In case sessionstore.js file does not exist or is corrupted (something
+   * happened between backup and write), attempt to read the sessionstore.bak
+   * instead.
+   */
+  read: function ssfi_read() {
+    let self = this;
+    return TaskUtils.spawn(function task() {
+      // Specify |outExecutionDuration| option to hold the combined duration of
+      // the asynchronous reads off the main thread (of both sessionstore.js and
+      // sessionstore.bak, if necessary). If sessionstore.js does not exist or
+      // is corrupted, |outExecutionDuration| will register the time it took to
+      // attempt to read the file. It will then be subsequently incremented by
+      // the read time of sessionsore.bak.
+      let readOptions = {
+        outExecutionDuration: null
+      };
+      // First read the sessionstore.js.
+      let text = yield self.readAux(self.path, readOptions);
+      if (typeof text === "undefined") {
+        // If sessionstore.js does not exist or is corrupted, read the
+        // sessionstore.bak.
+        text = yield self.readAux(self.backupPath, readOptions);
+      }
+      // Return either the content of the sessionstore.bak if it was read
+      // successfully or an empty string otherwise.
+      throw new Task.Result(text || "");
+    });
+  },
+
+  write: function ssfi_write(aData) {
+    let refObj = {};
+    let self = this;
+    return TaskUtils.spawn(function task() {
+      let bytes = gEncoder.encode(aData);
+
+      try {
+        let promise = OS.File.writeAtomic(self.path, bytes, {tmpPath: self.path + ".tmp"});
+        yield promise;
+      } catch (ex) {
+        console.error("Could not write session state file: " + self.path, ex);
+      }
+    });
+  },
+
+  createBackupCopy: function ssfi_createBackupCopy() {
+    let backupCopyOptions = {
+      outExecutionDuration: null
+    };
+    let self = this;
+    return TaskUtils.spawn(function task() {
+      try {
+        yield OS.File.move(self.path, self.backupPath, backupCopyOptions);
+      } catch (ex if self._isNoSuchFile(ex)) {
+        // Ignore exceptions about non-existent files.
+      } catch (ex) {
+        console.error("Could not backup session state file: " + self.path, ex);
+        throw ex;
+      }
+    });
+  },
+
+  wipe: function ssfi_wipe() {
+    let self = this;
+    return TaskUtils.spawn(function task() {
+      try {
+        yield OS.File.remove(self.path);
+      } catch (ex if self._isNoSuchFile(ex)) {
+        // Ignore exceptions about non-existent files.
+      } catch (ex) {
+        console.error("Could not remove session state file: " + self.path, ex);
+        throw ex;
+      }
+
+      try {
+        yield OS.File.remove(self.backupPath);
+      } catch (ex if self._isNoSuchFile(ex)) {
+        // Ignore exceptions about non-existent files.
+      } catch (ex) {
+        console.error("Could not remove session state backup file: " + self.path, ex);
+        throw ex;
+      }
+    });
+  },
+
+  _isNoSuchFile: function ssfi_isNoSuchFile(aReason) {
+    return aReason instanceof OS.File.Error && aReason.becauseNoSuchFile;
+  }
+};

application/palemoon/components/sessionstore/content/aboutSessionRestore.js

@@ -0,0 +1,317 @@
+/* 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/. */
+
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+const Cu = Components.utils;
+
+var gStateObject;
+var gTreeData;
+
+// Page initialization
+
+window.onload = function() {
+  // the crashed session state is kept inside a textbox so that SessionStore picks it up
+  // (for when the tab is closed or the session crashes right again)
+  var sessionData = document.getElementById("sessionData");
+  if (!sessionData.value) {
+    document.getElementById("errorTryAgain").disabled = true;
+    return;
+  }
+
+  // remove unneeded braces (added for compatibility with Firefox 2.0 and 3.0)
+  if (sessionData.value.charAt(0) == '(')
+    sessionData.value = sessionData.value.slice(1, -1);
+  try {
+    gStateObject = JSON.parse(sessionData.value);
+  }
+  catch (exJSON) {
+    var s = new Cu.Sandbox("about:blank", {sandboxName: 'aboutSessionRestore'});
+    gStateObject = Cu.evalInSandbox("(" + sessionData.value + ")", s);
+    // If we couldn't parse the string with JSON.parse originally, make sure
+    // that the value in the textbox will be parsable.
+    sessionData.value = JSON.stringify(gStateObject);
+  }
+
+  // make sure the data is tracked to be restored in case of a subsequent crash
+  var event = document.createEvent("UIEvents");
+  event.initUIEvent("input", true, true, window, 0);
+  sessionData.dispatchEvent(event);
+
+  initTreeView();
+
+  document.getElementById("errorTryAgain").focus();
+};
+
+function initTreeView() {
+  var tabList = document.getElementById("tabList");
+  var winLabel = tabList.getAttribute("_window_label");
+
+  gTreeData = [];
+  gStateObject.windows.forEach(function(aWinData, aIx) {
+    var winState = {
+      label: winLabel.replace("%S", (aIx + 1)),
+      open: true,
+      checked: true,
+      ix: aIx
+    };
+    winState.tabs = aWinData.tabs.map(function(aTabData) {
+      var entry = aTabData.entries[aTabData.index - 1] || { url: "about:blank" };
+      var iconURL = aTabData.attributes && aTabData.attributes.image || null;
+      // don't initiate a connection just to fetch a favicon (see bug 462863)
+      if (/^https?:/.test(iconURL))
+        iconURL = "moz-anno:favicon:" + iconURL;
+      return {
+        label: entry.title || entry.url,
+        checked: true,
+        src: iconURL,
+        parent: winState
+      };
+    });
+    gTreeData.push(winState);
+    for (let tab of winState.tabs)
+      gTreeData.push(tab);
+  }, this);
+
+  tabList.view = treeView;
+  tabList.view.selection.select(0);
+}
+
+// User actions
+
+function restoreSession() {
+  document.getElementById("errorTryAgain").disabled = true;
+
+  // remove all unselected tabs from the state before restoring it
+  var ix = gStateObject.windows.length - 1;
+  for (var t = gTreeData.length - 1; t >= 0; t--) {
+    if (treeView.isContainer(t)) {
+      if (gTreeData[t].checked === 0)
+        // this window will be restored partially
+        gStateObject.windows[ix].tabs =
+          gStateObject.windows[ix].tabs.filter(function(aTabData, aIx)
+                                                 gTreeData[t].tabs[aIx].checked);
+      else if (!gTreeData[t].checked)
+        // this window won't be restored at all
+        gStateObject.windows.splice(ix, 1);
+      ix--;
+    }
+  }
+  var stateString = JSON.stringify(gStateObject);
+
+  var ss = Cc["@mozilla.org/browser/sessionstore;1"].getService(Ci.nsISessionStore);
+  var top = getBrowserWindow();
+
+  // if there's only this page open, reuse the window for restoring the session
+  if (top.gBrowser.tabs.length == 1) {
+    ss.setWindowState(top, stateString, true);
+    return;
+  }
+
+  // restore the session into a new window and close the current tab
+  var newWindow = top.openDialog(top.location, "_blank", "chrome,dialog=no,all");
+  newWindow.addEventListener("load", function() {
+    newWindow.removeEventListener("load", arguments.callee, true);
+    ss.setWindowState(newWindow, stateString, true);
+
+    var tabbrowser = top.gBrowser;
+    var tabIndex = tabbrowser.getBrowserIndexForDocument(document);
+    tabbrowser.removeTab(tabbrowser.tabs[tabIndex]);
+  }, true);
+}
+
+function startNewSession() {
+  var prefBranch = Cc["@mozilla.org/preferences-service;1"].getService(Ci.nsIPrefBranch);
+  if (prefBranch.getIntPref("browser.startup.page") == 0)
+    getBrowserWindow().gBrowser.loadURI("about:logopage");
+  else
+    getBrowserWindow().BrowserHome();
+}
+
+function onListClick(aEvent) {
+  // don't react to right-clicks
+  if (aEvent.button == 2)
+    return;
+
+  var cell = treeView.treeBox.getCellAt(aEvent.clientX, aEvent.clientY);
+  if (cell.col) {
+    // Restore this specific tab in the same window for middle/double/accel clicking
+    // on a tab's title.
+#ifdef XP_MACOSX
+    let accelKey = aEvent.metaKey;
+#else
+    let accelKey = aEvent.ctrlKey;
+#endif
+    if ((aEvent.button == 1 || aEvent.button == 0 && aEvent.detail == 2 || accelKey) &&
+        cell.col.id == "title" &&
+        !treeView.isContainer(cell.row)) {
+      restoreSingleTab(cell.row, aEvent.shiftKey);
+      aEvent.stopPropagation();
+    }
+    else if (cell.col.id == "restore")
+      toggleRowChecked(cell.row);
+  }
+}
+
+function onListKeyDown(aEvent) {
+  switch (aEvent.keyCode)
+  {
+  case KeyEvent.DOM_VK_SPACE:
+    toggleRowChecked(document.getElementById("tabList").currentIndex);
+    break;
+  case KeyEvent.DOM_VK_RETURN:
+    var ix = document.getElementById("tabList").currentIndex;
+    if (aEvent.ctrlKey && !treeView.isContainer(ix))
+      restoreSingleTab(ix, aEvent.shiftKey);
+    break;
+  case KeyEvent.DOM_VK_UP:
+  case KeyEvent.DOM_VK_DOWN:
+  case KeyEvent.DOM_VK_PAGE_UP:
+  case KeyEvent.DOM_VK_PAGE_DOWN:
+  case KeyEvent.DOM_VK_HOME:
+  case KeyEvent.DOM_VK_END:
+    aEvent.preventDefault(); // else the page scrolls unwantedly
+    break;
+  }
+}
+
+// Helper functions
+
+function getBrowserWindow() {
+  return window.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIWebNavigation)
+               .QueryInterface(Ci.nsIDocShellTreeItem).rootTreeItem
+               .QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindow);
+}
+
+function toggleRowChecked(aIx) {
+  var item = gTreeData[aIx];
+  item.checked = !item.checked;
+  treeView.treeBox.invalidateRow(aIx);
+
+  function isChecked(aItem) aItem.checked;
+
+  if (treeView.isContainer(aIx)) {
+    // (un)check all tabs of this window as well
+    for (let tab of item.tabs) {
+      tab.checked = item.checked;
+      treeView.treeBox.invalidateRow(gTreeData.indexOf(tab));
+    }
+  }
+  else {
+    // update the window's checkmark as well (0 means "partially checked")
+    item.parent.checked = item.parent.tabs.every(isChecked) ? true :
+                          item.parent.tabs.some(isChecked) ? 0 : false;
+    treeView.treeBox.invalidateRow(gTreeData.indexOf(item.parent));
+  }
+
+  document.getElementById("errorTryAgain").disabled = !gTreeData.some(isChecked);
+}
+
+function restoreSingleTab(aIx, aShifted) {
+  var tabbrowser = getBrowserWindow().gBrowser;
+  var newTab = tabbrowser.addTab();
+  var item = gTreeData[aIx];
+
+  var ss = Cc["@mozilla.org/browser/sessionstore;1"].getService(Ci.nsISessionStore);
+  var tabState = gStateObject.windows[item.parent.ix]
+                             .tabs[aIx - gTreeData.indexOf(item.parent) - 1];
+  // ensure tab would be visible on the tabstrip.
+  tabState.hidden = false;
+  ss.setTabState(newTab, JSON.stringify(tabState));
+
+  // respect the preference as to whether to select the tab (the Shift key inverses)
+  var prefBranch = Cc["@mozilla.org/preferences-service;1"].getService(Ci.nsIPrefBranch);
+  if (prefBranch.getBoolPref("browser.tabs.loadInBackground") != !aShifted)
+    tabbrowser.selectedTab = newTab;
+}
+
+// Tree controller
+
+var treeView = {
+  treeBox: null,
+  selection: null,
+
+  get rowCount()                     { return gTreeData.length; },
+  setTree: function(treeBox)         { this.treeBox = treeBox; },
+  getCellText: function(idx, column) { return gTreeData[idx].label; },
+  isContainer: function(idx)         { return "open" in gTreeData[idx]; },
+  getCellValue: function(idx, column){ return gTreeData[idx].checked; },
+  isContainerOpen: function(idx)     { return gTreeData[idx].open; },
+  isContainerEmpty: function(idx)    { return false; },
+  isSeparator: function(idx)         { return false; },
+  isSorted: function()               { return false; },
+  isEditable: function(idx, column)  { return false; },
+  canDrop: function(idx, orientation, dt) { return false; },
+  getLevel: function(idx)            { return this.isContainer(idx) ? 0 : 1; },
+
+  getParentIndex: function(idx) {
+    if (!this.isContainer(idx))
+      for (var t = idx - 1; t >= 0 ; t--)
+        if (this.isContainer(t))
+          return t;
+    return -1;
+  },
+
+  hasNextSibling: function(idx, after) {
+    var thisLevel = this.getLevel(idx);
+    for (var t = after + 1; t < gTreeData.length; t++)
+      if (this.getLevel(t) <= thisLevel)
+        return this.getLevel(t) == thisLevel;
+    return false;
+  },
+
+  toggleOpenState: function(idx) {
+    if (!this.isContainer(idx))
+      return;
+    var item = gTreeData[idx];
+    if (item.open) {
+      // remove this window's tab rows from the view
+      var thisLevel = this.getLevel(idx);
+      for (var t = idx + 1; t < gTreeData.length && this.getLevel(t) > thisLevel; t++);
+      var deletecount = t - idx - 1;
+      gTreeData.splice(idx + 1, deletecount);
+      this.treeBox.rowCountChanged(idx + 1, -deletecount);
+    }
+    else {
+      // add this window's tab rows to the view
+      var toinsert = gTreeData[idx].tabs;
+      for (var i = 0; i < toinsert.length; i++)
+        gTreeData.splice(idx + i + 1, 0, toinsert[i]);
+      this.treeBox.rowCountChanged(idx + 1, toinsert.length);
+    }
+    item.open = !item.open;
+    this.treeBox.invalidateRow(idx);
+  },
+
+  getCellProperties: function(idx, column) {
+    if (column.id == "restore" && this.isContainer(idx) && gTreeData[idx].checked === 0)
+      return "partial";
+    if (column.id == "title")
+      return this.getImageSrc(idx, column) ? "icon" : "noicon";
+
+    return "";
+  },
+
+  getRowProperties: function(idx) {
+    var winState = gTreeData[idx].parent || gTreeData[idx];
+    if (winState.ix % 2 != 0)
+      return "alternate";
+
+    return "";
+  },
+
+  getImageSrc: function(idx, column) {
+    if (column.id == "title")
+      return gTreeData[idx].src || null;
+    return null;
+  },
+
+  getProgressMode : function(idx, column) { },
+  cycleHeader: function(column) { },
+  cycleCell: function(idx, column) { },
+  selectionChanged: function() { },
+  performAction: function(action) { },
+  performActionOnCell: function(action, index, column) { },
+  getColumnProperties: function(column) { return ""; }
+};

application/palemoon/components/sessionstore/content/aboutSessionRestore.xhtml

@@ -0,0 +1,94 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+# 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/.
+-->
+<!DOCTYPE html [
+  <!ENTITY % htmlDTD PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "DTD/xhtml1-strict.dtd">
+  %htmlDTD;
+  <!ENTITY % netErrorDTD SYSTEM "chrome://global/locale/netError.dtd">
+  %netErrorDTD;
+  <!ENTITY % globalDTD SYSTEM "chrome://global/locale/global.dtd">
+  %globalDTD;
+  <!ENTITY % restorepageDTD SYSTEM "chrome://browser/locale/aboutSessionRestore.dtd">
+  %restorepageDTD;
+]>
+
+<html xmlns="http://www.w3.org/1999/xhtml">
+  <head>
+    <title>&restorepage.tabtitle;</title>
+    <link rel="stylesheet" href="chrome://global/skin/netError.css" type="text/css" media="all"/>
+    <link rel="stylesheet" href="chrome://browser/skin/aboutSessionRestore.css" type="text/css" media="all"/>
+    <link rel="icon" type="image/png" href="chrome://global/skin/icons/warning-16.png"/>
+
+    <script type="application/javascript;version=1.8" src="chrome://browser/content/aboutSessionRestore.js"/>
+  </head>
+
+  <body dir="&locale.dir;">
+
+    <!-- PAGE CONTAINER (for styling purposes only) -->
+    <div id="errorPageContainer">
+
+      <!-- Error Title -->
+      <div id="errorTitle">
+        <h1 id="errorTitleText">&restorepage.errorTitle;</h1>
+      </div>
+
+      <!-- LONG CONTENT (the section most likely to require scrolling) -->
+      <div id="errorLongContent">
+
+        <!-- Short Description -->
+        <div id="errorShortDesc">
+          <p id="errorShortDescText">&restorepage.problemDesc;</p>
+        </div>
+
+        <!-- Long Description (Note: See netError.dtd for used XHTML tags) -->
+        <div id="errorLongDesc">
+          <p>&restorepage.tryThis;</p>
+          <ul>
+            <li>&restorepage.restoreSome;</li>
+            <li>&restorepage.startNew;</li>
+          </ul>
+        </div>
+
+        <!-- Short Description -->
+        <div id="errorTrailerDesc">
+          <tree xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
+                id="tabList" flex="1" seltype="single" hidecolumnpicker="true"
+                onclick="onListClick(event);" onkeydown="onListKeyDown(event);"
+                _window_label="&restorepage.windowLabel;">
+            <treecols>
+              <treecol cycler="true" id="restore" type="checkbox" label="&restorepage.restoreHeader;"/>
+              <splitter class="tree-splitter"/>
+              <treecol primary="true" id="title" label="&restorepage.listHeader;" flex="1"/>
+            </treecols>
+            <treechildren flex="1"/>
+          </tree>
+        </div>
+      </div>
+
+      <!-- Buttons -->
+      <hbox xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul" id="buttons">
+#ifdef XP_UNIX
+        <button id="errorCancel" label="&restorepage.closeButton;"
+                accesskey="&restorepage.close.access;"
+                oncommand="startNewSession();"/>
+        <button id="errorTryAgain" label="&restorepage.tryagainButton;"
+                accesskey="&restorepage.restore.access;"
+                oncommand="restoreSession();"/>
+#else
+        <button id="errorTryAgain" label="&restorepage.tryagainButton;"
+                accesskey="&restorepage.restore.access;"
+                oncommand="restoreSession();"/>
+        <button id="errorCancel" label="&restorepage.closeButton;"
+                accesskey="&restorepage.close.access;"
+                oncommand="startNewSession();"/>
+#endif
+      </hbox>
+      <!-- holds the session data for when the tab is closed -->
+      <input type="text" id="sessionData" style="display: none;"/>
+    </div>
+
+  </body>
+</html>

application/palemoon/components/sessionstore/content/content-sessionStore.js

@@ -0,0 +1,40 @@
+/* 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/. */
+
+function debug(msg) {
+  Services.console.logStringMessage("SessionStoreContent: " + msg);
+}
+
+/**
+ * Listens for and handles content events that we need for the
+ * session store service to be notified of state changes in content.
+ */
+let EventListener = {
+
+  DOM_EVENTS: [
+    "pageshow", "change", "input"
+  ],
+
+  init: function () {
+    this.DOM_EVENTS.forEach(e => addEventListener(e, this, true));
+  },
+
+  handleEvent: function (event) {
+    switch (event.type) {
+      case "pageshow":
+        if (event.persisted)
+          sendAsyncMessage("SessionStore:pageshow");
+        break;
+      case "input":
+      case "change":
+        sendAsyncMessage("SessionStore:input");
+        break;
+      default:
+        debug("received unknown event '" + event.type + "'");
+        break;
+    }
+  }
+};
+
+EventListener.init();

application/palemoon/components/sessionstore/jar.mn

@@ -0,0 +1,8 @@
+# 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/.
+
+browser.jar:
+*   content/browser/aboutSessionRestore.xhtml             (content/aboutSessionRestore.xhtml)
+*   content/browser/aboutSessionRestore.js                (content/aboutSessionRestore.js)
+    content/browser/content-sessionStore.js               (content/content-sessionStore.js)

application/palemoon/components/sessionstore/moz.build

@@ -0,0 +1,31 @@
+# -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# 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/.
+
+JAR_MANIFESTS += ['jar.mn']
+
+XPIDL_SOURCES += [
+    'nsISessionStartup.idl',
+    'nsISessionStore.idl',
+]
+
+XPIDL_MODULE = 'sessionstore'
+
+EXTRA_COMPONENTS += [
+    'nsSessionStartup.js',
+    'nsSessionStore.js',
+    'nsSessionStore.manifest',
+]
+
+EXTRA_JS_MODULES.sessionstore = [
+    '_SessionFile.jsm',
+    'DocumentUtils.jsm',
+    'SessionStorage.jsm',
+    'XPathGenerator.jsm',
+]
+
+EXTRA_PP_JS_MODULES.sessionstore += [
+    'SessionStore.jsm',
+]

application/palemoon/components/sessionstore/nsISessionStartup.idl

@@ -0,0 +1,59 @@
+/* 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/. */
+
+#include "nsISupports.idl"
+
+/**
+ * nsISessionStore keeps track of the current browsing state - i.e.
+ * tab history, cookies, scroll state, form data, POSTDATA and window features
+ * - and allows to restore everything into one window.
+ */
+
+[scriptable, uuid(51f4b9f0-f3d2-11e2-bb62-2c24dd830245)]
+interface nsISessionStartup: nsISupports
+{
+  /**
+   * Return a promise that is resolved once initialization
+   * is complete.
+   */
+  readonly attribute jsval onceInitialized;
+
+  // Get session state
+  readonly attribute jsval state;
+
+  /**
+   * Determines whether there is a pending session restore and makes sure that
+   * we're initialized before returning. If we're not yet this will read the
+   * session file synchronously.
+   */
+  boolean doRestore();
+
+  /**
+   * Returns whether we will restore a session that ends up replacing the
+   * homepage. The browser uses this to not start loading the homepage if
+   * we're going to stop its load anyway shortly after.
+   *
+   * This is meant to be an optimization for the average case that loading the
+   * session file finishes before we may want to start loading the default
+   * homepage. Should this be called before the session file has been read it
+   * will just return false.
+   */
+  readonly attribute bool willOverrideHomepage;
+
+  /**
+   * What type of session we're restoring.
+   * NO_SESSION       There is no data available from the previous session
+   * RECOVER_SESSION  The last session crashed. It will either be restored or
+   *                  about:sessionrestore will be shown.
+   * RESUME_SESSION   The previous session should be restored at startup
+   * DEFER_SESSION    The previous session is fine, but it shouldn't be restored
+   *                  without explicit action (with the exception of pinned tabs)
+   */
+  const unsigned long NO_SESSION = 0;
+  const unsigned long RECOVER_SESSION = 1;
+  const unsigned long RESUME_SESSION = 2;
+  const unsigned long DEFER_SESSION = 3;
+
+  readonly attribute unsigned long sessionType;
+};

application/palemoon/components/sessionstore/nsISessionStore.idl

@@ -0,0 +1,206 @@
+/* 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/. */
+
+#include "nsISupports.idl"
+
+interface nsIDOMWindow;
+interface nsIDOMNode;
+
+/**
+ * nsISessionStore keeps track of the current browsing state - i.e.
+ * tab history, cookies, scroll state, form data, POSTDATA and window features
+ * - and allows to restore everything into one browser window.
+ *
+ * The nsISessionStore API operates mostly on browser windows and the tabbrowser
+ * tabs contained in them:
+ *
+ * * "Browser windows" are those DOM windows having loaded
+ * chrome://browser/content/browser.xul . From overlays you can just pass the
+ * global |window| object to the API, though (or |top| from a sidebar).
+ * From elsewhere you can get browser windows through the nsIWindowMediator
+ * by looking for "navigator:browser" windows.
+ *
+ * * "Tabbrowser tabs" are all the child nodes of a browser window's
+ * |gBrowser.tabContainer| such as e.g. |gBrowser.selectedTab|.
+ */
+
+[scriptable, uuid(43ec216b-f002-4424-bfc5-fc555c87dbc4)]
+interface nsISessionStore : nsISupports
+{
+  /**
+   * Initialize the service
+   */
+  jsval init(in nsIDOMWindow aWindow);
+
+  /**
+   * Is it possible to restore the previous session. Will always be false when
+   * in Private Browsing mode.
+   */
+  attribute boolean canRestoreLastSession;
+
+  /**
+   * Restore the previous session if possible. This will not overwrite the
+   * current session. Instead the previous session will be merged into the
+   * current session. Current windows will be reused if they were windows that
+   * pinned tabs were previously restored into. New windows will be opened as
+   * needed.
+   *
+   * Note: This will throw if there is no previous state to restore. Check with
+   * canRestoreLastSession first to avoid thrown errors.
+   */
+  void restoreLastSession();
+
+  /**
+   * Get the current browsing state.
+   * @returns a JSON string representing the session state.
+   */
+  AString getBrowserState();
+
+  /**
+   * Set the browsing state.
+   * This will immediately restore the state of the whole application to the state
+   * passed in, *replacing* the current session.
+   *
+   * @param aState is a JSON string representing the session state.
+   */
+  void setBrowserState(in AString aState);
+
+  /**
+   * @param aWindow is the browser window whose state is to be returned.
+   *
+   * @returns a JSON string representing a session state with only one window.
+   */
+  AString getWindowState(in nsIDOMWindow aWindow);
+
+  /**
+   * @param aWindow    is the browser window whose state is to be set.
+   * @param aState     is a JSON string representing a session state.
+   * @param aOverwrite boolean overwrite existing tabs
+   */
+  void setWindowState(in nsIDOMWindow aWindow, in AString aState, in boolean aOverwrite);
+
+  /**
+   * @param aTab is the tabbrowser tab whose state is to be returned.
+   *
+   * @returns a JSON string representing the state of the tab
+   *         (note: doesn't contain cookies - if you need them, use getWindowState instead).
+   */
+  AString getTabState(in nsIDOMNode aTab);
+
+  /**
+   * @param aTab   is the tabbrowser tab whose state is to be set.
+   * @param aState is a JSON string representing a session state.
+   */
+  void setTabState(in nsIDOMNode aTab, in AString aState);
+
+  /**
+   * Duplicates a given tab as thoroughly as possible.
+   *
+   * @param aWindow is the browser window into which the tab will be duplicated.
+   * @param aTab    is the tabbrowser tab to duplicate (can be from a different window).
+   * @param aDelta  is the offset to the history entry to load in the duplicated tab.
+   * @returns a reference to the newly created tab.
+   */
+  nsIDOMNode duplicateTab(in nsIDOMWindow aWindow, in nsIDOMNode aTab,
+                          [optional] in long aDelta);
+
+  /**
+   * Get the number of restore-able tabs for a browser window
+   */
+  unsigned long getClosedTabCount(in nsIDOMWindow aWindow);
+
+  /**
+   * Get closed tab data
+   *
+   * @param aWindow is the browser window for which to get closed tab data
+   * @returns a JSON string representing the list of closed tabs.
+   */
+  AString getClosedTabData(in nsIDOMWindow aWindow);
+
+  /**
+   * @param aWindow is the browser window to reopen a closed tab in.
+   * @param aIndex  is the index of the tab to be restored (FIFO ordered).
+   * @returns a reference to the reopened tab.
+   */
+  nsIDOMNode undoCloseTab(in nsIDOMWindow aWindow, in unsigned long aIndex);
+
+  /**
+   * @param aWindow is the browser window associated with the closed tab.
+   * @param aIndex  is the index of the closed tab to be removed (FIFO ordered).
+   */
+  nsIDOMNode forgetClosedTab(in nsIDOMWindow aWindow, in unsigned long aIndex);
+
+  /**
+   * Get the number of restore-able windows
+   */
+  unsigned long getClosedWindowCount();
+
+  /**
+   * Get closed windows data
+   *
+   * @returns a JSON string representing the list of closed windows.
+   */
+  AString getClosedWindowData();
+
+  /**
+   * @param aIndex is the index of the windows to be restored (FIFO ordered).
+   * @returns the nsIDOMWindow object of the reopened window
+   */
+  nsIDOMWindow undoCloseWindow(in unsigned long aIndex);
+
+  /**
+   * @param aIndex  is the index of the closed window to be removed (FIFO ordered).
+   *
+   * @throws NS_ERROR_INVALID_ARG
+   *   when aIndex does not map to a closed window
+   */
+  nsIDOMNode forgetClosedWindow(in unsigned long aIndex);
+
+  /**
+   * @param aWindow is the window to get the value for.
+   * @param aKey    is the value's name.
+   *
+   * @returns A string value or an empty string if none is set.
+   */
+  AString getWindowValue(in nsIDOMWindow aWindow, in AString aKey);
+
+  /**
+   * @param aWindow      is the browser window to set the value for.
+   * @param aKey         is the value's name.
+   * @param aStringValue is the value itself (use JSON.stringify/parse before setting JS objects).
+   */
+  void setWindowValue(in nsIDOMWindow aWindow, in AString aKey, in AString aStringValue);
+
+  /**
+   * @param aWindow is the browser window to get the value for.
+   * @param aKey    is the value's name.
+   */
+  void deleteWindowValue(in nsIDOMWindow aWindow, in AString aKey);
+
+  /**
+   * @param aTab is the tabbrowser tab to get the value for.
+   * @param aKey is the value's name.
+   *
+   * @returns A string value or an empty string if none is set.
+   */
+  AString getTabValue(in nsIDOMNode aTab, in AString aKey);
+
+  /**
+   * @param aTab         is the tabbrowser tab to set the value for.
+   * @param aKey         is the value's name.
+   * @param aStringValue is the value itself (use JSON.stringify/parse before setting JS objects).
+   */
+  void setTabValue(in nsIDOMNode aTab, in AString aKey, in AString aStringValue);
+
+  /**
+   * @param aTab is the tabbrowser tab to get the value for.
+   * @param aKey is the value's name.
+   */
+  void deleteTabValue(in nsIDOMNode aTab, in AString aKey);
+
+  /**
+   * @param aName is the name of the attribute to save/restore for all tabbrowser tabs.
+   */
+  void persistTabAttribute(in AString aName);
+};

application/palemoon/components/sessionstore/nsSessionStartup.js

@@ -0,0 +1,291 @@
+/* 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/. */
+
+/**
+ * Session Storage and Restoration
+ *
+ * Overview
+ * This service reads user's session file at startup, and makes a determination
+ * as to whether the session should be restored. It will restore the session
+ * under the circumstances described below.  If the auto-start Private Browsing
+ * mode is active, however, the session is never restored.
+ *
+ * Crash Detection
+ * The session file stores a session.state property, that
+ * indicates whether the browser is currently running. When the browser shuts
+ * down, the field is changed to "stopped". At startup, this field is read, and
+ * if its value is "running", then it's assumed that the browser had previously
+ * crashed, or at the very least that something bad happened, and that we should
+ * restore the session.
+ *
+ * Forced Restarts
+ * In the event that a restart is required due to application update or extension
+ * installation, set the browser.sessionstore.resume_session_once pref to true,
+ * and the session will be restored the next time the browser starts.
+ *
+ * Always Resume
+ * This service will always resume the session if the integer pref
+ * browser.startup.page is set to 3.
+ */
+
+/* :::::::: Constants and Helpers ::::::::::::::: */
+
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+const Cr = Components.results;
+const Cu = Components.utils;
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/PrivateBrowsingUtils.jsm");
+Cu.import("resource://gre/modules/Promise.jsm");
+
+XPCOMUtils.defineLazyModuleGetter(this, "_SessionFile",
+  "resource:///modules/sessionstore/_SessionFile.jsm");
+
+const STATE_RUNNING_STR = "running";
+
+function debug(aMsg) {
+  aMsg = ("SessionStartup: " + aMsg).replace(/\S{80}/g, "$&\n");
+  Services.console.logStringMessage(aMsg);
+}
+
+let gOnceInitializedDeferred = Promise.defer();
+
+/* :::::::: The Service ::::::::::::::: */
+
+function SessionStartup() {
+}
+
+SessionStartup.prototype = {
+
+  // the state to restore at startup
+  _initialState: null,
+  _sessionType: Ci.nsISessionStartup.NO_SESSION,
+  _initialized: false,
+
+/* ........ Global Event Handlers .............. */
+
+  /**
+   * Initialize the component
+   */
+  init: function sss_init() {
+    // do not need to initialize anything in auto-started private browsing sessions
+    if (PrivateBrowsingUtils.permanentPrivateBrowsing) {
+      this._initialized = true;
+      gOnceInitializedDeferred.resolve();
+      return;
+    }
+
+    _SessionFile.read().then(
+      this._onSessionFileRead.bind(this)
+    );
+  },
+
+  // Wrap a string as a nsISupports
+  _createSupportsString: function ssfi_createSupportsString(aData) {
+    let string = Cc["@mozilla.org/supports-string;1"]
+                   .createInstance(Ci.nsISupportsString);
+    string.data = aData;
+    return string;
+  },
+
+  _onSessionFileRead: function sss_onSessionFileRead(aStateString) {
+    if (this._initialized) {
+      // Initialization is complete, nothing else to do
+      return;
+    }
+    try {
+      this._initialized = true;
+
+      // Let observers modify the state before it is used
+      let supportsStateString = this._createSupportsString(aStateString);
+      Services.obs.notifyObservers(supportsStateString, "sessionstore-state-read", "");
+      aStateString = supportsStateString.data;
+
+      // No valid session found.
+      if (!aStateString) {
+        this._sessionType = Ci.nsISessionStartup.NO_SESSION;
+        return;
+      }
+
+      // parse the session state into a JS object
+      // remove unneeded braces (added for compatibility with Firefox 2.0 and 3.0)
+      if (aStateString.charAt(0) == '(')
+        aStateString = aStateString.slice(1, -1);
+      let corruptFile = false;
+      try {
+        this._initialState = JSON.parse(aStateString);
+      }
+      catch (ex) {
+        debug("The session file contained un-parse-able JSON: " + ex);
+        // This is not valid JSON, but this might still be valid JavaScript,
+        // as used in FF2/FF3, so we need to eval.
+        // evalInSandbox will throw if aStateString is not parse-able.
+        try {
+          var s = new Cu.Sandbox("about:blank", {sandboxName: 'nsSessionStartup'});
+          this._initialState = Cu.evalInSandbox("(" + aStateString + ")", s);
+        } catch(ex) {
+          debug("The session file contained un-eval-able JSON: " + ex);
+          corruptFile = true;
+        }
+      }
+      let doResumeSessionOnce = Services.prefs.getBoolPref("browser.sessionstore.resume_session_once");
+      let doResumeSession = doResumeSessionOnce ||
+            Services.prefs.getIntPref("browser.startup.page") == 3;
+
+      // If this is a normal restore then throw away any previous session
+      if (!doResumeSessionOnce)
+        delete this._initialState.lastSessionState;
+
+      let resumeFromCrash = Services.prefs.getBoolPref("browser.sessionstore.resume_from_crash");
+      let lastSessionCrashed =
+        this._initialState && this._initialState.session &&
+        this._initialState.session.state &&
+        this._initialState.session.state == STATE_RUNNING_STR;
+
+      // set the startup type
+      if (lastSessionCrashed && resumeFromCrash)
+        this._sessionType = Ci.nsISessionStartup.RECOVER_SESSION;
+      else if (!lastSessionCrashed && doResumeSession)
+        this._sessionType = Ci.nsISessionStartup.RESUME_SESSION;
+      else if (this._initialState)
+        this._sessionType = Ci.nsISessionStartup.DEFER_SESSION;
+      else
+        this._initialState = null; // reset the state
+
+      Services.obs.addObserver(this, "sessionstore-windows-restored", true);
+
+      if (this._sessionType != Ci.nsISessionStartup.NO_SESSION)
+        Services.obs.addObserver(this, "browser:purge-session-history", true);
+
+    } finally {
+      // We're ready. Notify everyone else.
+      Services.obs.notifyObservers(null, "sessionstore-state-finalized", "");
+      gOnceInitializedDeferred.resolve();
+    }
+  },
+
+  /**
+   * Handle notifications
+   */
+  observe: function sss_observe(aSubject, aTopic, aData) {
+    switch (aTopic) {
+    case "app-startup":
+      Services.obs.addObserver(this, "final-ui-startup", true);
+      Services.obs.addObserver(this, "quit-application", true);
+      break;
+    case "final-ui-startup":
+      Services.obs.removeObserver(this, "final-ui-startup");
+      Services.obs.removeObserver(this, "quit-application");
+      this.init();
+      break;
+    case "quit-application":
+      // no reason for initializing at this point (cf. bug 409115)
+      Services.obs.removeObserver(this, "final-ui-startup");
+      Services.obs.removeObserver(this, "quit-application");
+      if (this._sessionType != Ci.nsISessionStartup.NO_SESSION)
+        Services.obs.removeObserver(this, "browser:purge-session-history");
+      break;
+    case "sessionstore-windows-restored":
+      Services.obs.removeObserver(this, "sessionstore-windows-restored");
+      // free _initialState after nsSessionStore is done with it
+      this._initialState = null;
+      break;
+    case "browser:purge-session-history":
+      Services.obs.removeObserver(this, "browser:purge-session-history");
+      // reset all state on sanitization
+      this._sessionType = Ci.nsISessionStartup.NO_SESSION;
+      break;
+    }
+  },
+
+/* ........ Public API ................*/
+
+  get onceInitialized() {
+    return gOnceInitializedDeferred.promise;
+  },
+
+  /**
+   * Get the session state as a jsval
+   */
+  get state() {
+    this._ensureInitialized();
+    return this._initialState;
+  },
+
+  /**
+   * Determines whether there is a pending session restore and makes sure that
+   * we're initialized before returning. If we're not yet this will read the
+   * session file synchronously.
+   * @returns bool
+   */
+  doRestore: function sss_doRestore() {
+    this._ensureInitialized();
+    return this._willRestore();
+  },
+
+  /**
+   * Determines whether there is a pending session restore.
+   * @returns bool
+   */
+  _willRestore: function () {
+    return this._sessionType == Ci.nsISessionStartup.RECOVER_SESSION ||
+           this._sessionType == Ci.nsISessionStartup.RESUME_SESSION;
+  },
+
+  /**
+   * Returns whether we will restore a session that ends up replacing the
+   * homepage. The browser uses this to not start loading the homepage if
+   * we're going to stop its load anyway shortly after.
+   *
+   * This is meant to be an optimization for the average case that loading the
+   * session file finishes before we may want to start loading the default
+   * homepage. Should this be called before the session file has been read it
+   * will just return false.
+   *
+   * @returns bool
+   */
+  get willOverrideHomepage() {
+    if (this._initialState && this._willRestore()) {
+      let windows = this._initialState.windows || null;
+      // If there are valid windows with not only pinned tabs, signal that we
+      // will override the default homepage by restoring a session.
+      return windows && windows.some(w => w.tabs.some(t => !t.pinned));
+    }
+    return false;
+  },
+
+  /**
+   * Get the type of pending session store, if any.
+   */
+  get sessionType() {
+    this._ensureInitialized();
+    return this._sessionType;
+  },
+
+  // Ensure that initialization is complete.
+  // If initialization is not complete yet, fall back to a synchronous
+  // initialization and kill ongoing asynchronous initialization
+  _ensureInitialized: function sss__ensureInitialized() {
+    try {
+      if (this._initialized) {
+        // Initialization is complete, nothing else to do
+        return;
+      }
+      let contents = _SessionFile.syncRead();
+      this._onSessionFileRead(contents);
+    } catch(ex) {
+      debug("ensureInitialized: could not read session " + ex + ", " + ex.stack);
+      throw ex;
+    }
+  },
+
+  /* ........ QueryInterface .............. */
+  QueryInterface : XPCOMUtils.generateQI([Ci.nsIObserver,
+                                          Ci.nsISupportsWeakReference,
+                                          Ci.nsISessionStartup]),
+  classID:          Components.ID("{ec7a6c20-e081-11da-8ad9-0800200c9a66}")
+};
+
+this.NSGetFactory = XPCOMUtils.generateNSGetFactory([SessionStartup]);

application/palemoon/components/sessionstore/nsSessionStore.js

@@ -0,0 +1,37 @@
+/* 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/. */
+
+/**
+ * Session Storage and Restoration
+ *
+ * Overview
+ * This service keeps track of a user's session, storing the various bits
+ * required to return the browser to its current state. The relevant data is
+ * stored in memory, and is periodically saved to disk in a file in the
+ * profile directory. The service is started at first window load, in
+ * delayedStartup, and will restore the session from the data received from
+ * the nsSessionStartup service.
+ */
+
+const Cu = Components.utils;
+const Ci = Components.interfaces;
+
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource:///modules/sessionstore/SessionStore.jsm");
+
+function SessionStoreService() {}
+
+// The SessionStore module's object is frozen. We need to modify our prototype
+// and add some properties so let's just copy the SessionStore object.
+Object.keys(SessionStore).forEach(function (aName) {
+  let desc = Object.getOwnPropertyDescriptor(SessionStore, aName);
+  Object.defineProperty(SessionStoreService.prototype, aName, desc);
+});
+
+SessionStoreService.prototype.classID =
+  Components.ID("{5280606b-2510-4fe0-97ef-9b5a22eafe6b}");
+SessionStoreService.prototype.QueryInterface =
+  XPCOMUtils.generateQI([Ci.nsISessionStore]);
+
+this.NSGetFactory = XPCOMUtils.generateNSGetFactory([SessionStoreService]);

application/palemoon/components/sessionstore/nsSessionStore.manifest

@@ -0,0 +1,18 @@
+# WebappRT doesn't need these instructions, and they don't necessarily work
+# with it, but it does use a GRE directory that the GRE shares with Firefox,
+# so in order to prevent the instructions from being processed for WebappRT,
+# we need to restrict them to the applications that depend on them, i.e.:
+#
+#   b2g:            {3c2e2abc-06d4-11e1-ac3b-374f68613e61}
+#   browser:        {8de7fcbb-c55c-4fbe-bfc5-fc555c87dbc4}
+#   mobile/android: {aa3c5121-dab2-40e2-81ca-7ea25febc110}
+#   mobile/xul:     {a23983c0-fd0e-11dc-95ff-0800200c9a66}
+#
+# In theory we should do this for all these instructions, but in practice it is
+# sufficient to do it for the app-startup one, and the file is simpler that way.
+
+component {5280606b-2510-4fe0-97ef-9b5a22eafe6b} nsSessionStore.js
+contract @mozilla.org/browser/sessionstore;1 {5280606b-2510-4fe0-97ef-9b5a22eafe6b}
+component {ec7a6c20-e081-11da-8ad9-0800200c9a66} nsSessionStartup.js
+contract @mozilla.org/browser/sessionstartup;1 {ec7a6c20-e081-11da-8ad9-0800200c9a66}
+category app-startup nsSessionStartup service,@mozilla.org/browser/sessionstartup;1 application={3c2e2abc-06d4-11e1-ac3b-374f68613e61} application={8de7fcbb-c55c-4fbe-bfc5-fc555c87dbc4} application={aa3c5121-dab2-40e2-81ca-7ea25febc110} application={a23983c0-fd0e-11dc-95ff-0800200c9a66}