Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1149 insertions, 0 deletions

diff --git a/toolkit/components/places/BookmarkHTMLUtils.sys.mjs b/toolkit/components/places/BookmarkHTMLUtils.sys.mjs
new file mode 100644
index 0000000000..ec6acb5e10
--- /dev/null
+++ b/toolkit/components/places/BookmarkHTMLUtils.sys.mjs
@@ -0,0 +1,1149 @@
+/* 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 file works on the old-style "bookmarks.html" file.  It includes
+ * functions to import and export existing bookmarks to this file format.
+ *
+ * Format
+ * ------
+ *
+ * Primary heading := h1
+ *   Old version used this to set attributes on the bookmarks RDF root, such
+ *   as the last modified date. We only use H1 to check for the attribute
+ *   PLACES_ROOT, which tells us that this hierarchy root is the places root.
+ *   For backwards compatibility, if we don't find this, we assume that the
+ *   hierarchy is rooted at the bookmarks menu.
+ * Heading := any heading other than h1
+ *   Old version used this to set attributes on the current container. We only
+ *   care about the content of the heading container, which contains the title
+ *   of the bookmark container.
+ * Bookmark := a
+ *   HREF is the destination of the bookmark
+ *   FEEDURL is the URI of the RSS feed. This is deprecated and no more
+ *   supported, but some old files may still contain it.
+ *   LAST_CHARSET is stored as an annotation so that the next time we go to
+ *     that page we remember the user's preference.
+ *   ICON will be stored in the favicon service
+ *   ICON_URI is new for places bookmarks.html, it refers to the original
+ *     URI of the favicon so we don't have to make up favicon URLs.
+ *   Text of the <a> container is the name of the bookmark
+ *   Ignored: LAST_VISIT, ID (writing out non-RDF IDs can confuse Firefox 2)
+ * Bookmark comment := dd
+ *   This affects the previosly added bookmark
+ * Separator := hr
+ *   Insert a separator into the current container
+ * The folder hierarchy is defined by <dl>/<ul>/<menu> (the old importing code
+ *     handles all these cases, when we write, use <dl>).
+ *
+ * Overall design
+ * --------------
+ *
+ * We need to emulate a recursive parser. A "Bookmark import frame" is created
+ * corresponding to each folder we encounter. These are arranged in a stack,
+ * and contain all the state we need to keep track of.
+ *
+ * A frame is created when we find a heading, which defines a new container.
+ * The frame also keeps track of the nesting of <DL>s, (in well-formed
+ * bookmarks files, these will have a 1-1 correspondence with frames, but we
+ * try to be a little more flexible here). When the nesting count decreases
+ * to 0, then we know a frame is complete and to pop back to the previous
+ * frame.
+ *
+ * Note that a lot of things happen when tags are CLOSED because we need to
+ * get the text from the content of the tag. For example, link and heading tags
+ * both require the content (= title) before actually creating it.
+ */
+
+const { NetUtil } = ChromeUtils.import("resource://gre/modules/NetUtil.jsm");
+import { FileUtils } from "resource://gre/modules/FileUtils.sys.mjs";
+import { PlacesUtils } from "resource://gre/modules/PlacesUtils.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  PlacesBackups: "resource://gre/modules/PlacesBackups.sys.mjs",
+});
+
+const Container_Normal = 0;
+const Container_Toolbar = 1;
+const Container_Menu = 2;
+const Container_Unfiled = 3;
+const Container_Places = 4;
+
+const MICROSEC_PER_SEC = 1000000;
+
+const EXPORT_INDENT = "    "; // four spaces
+
+function base64EncodeString(aString) {
+  let stream = Cc["@mozilla.org/io/string-input-stream;1"].createInstance(
+    Ci.nsIStringInputStream
+  );
+  stream.setData(aString, aString.length);
+  let encoder = Cc["@mozilla.org/scriptablebase64encoder;1"].createInstance(
+    Ci.nsIScriptableBase64Encoder
+  );
+  return encoder.encodeToString(stream, aString.length);
+}
+
+/**
+ * Provides HTML escaping for use in HTML attributes and body of the bookmarks
+ * file, compatible with the old bookmarks system.
+ */
+function escapeHtmlEntities(aText) {
+  return (aText || "")
+    .replace(/&/g, "&amp;")
+    .replace(/</g, "&lt;")
+    .replace(/>/g, "&gt;")
+    .replace(/"/g, "&quot;")
+    .replace(/'/g, "&#39;");
+}
+
+/**
+ * Provides URL escaping for use in HTML attributes of the bookmarks file,
+ * compatible with the old bookmarks system.
+ */
+function escapeUrl(aText) {
+  return (aText || "").replace(/"/g, "%22");
+}
+
+function notifyObservers(aTopic, aInitialImport) {
+  Services.obs.notifyObservers(
+    null,
+    aTopic,
+    aInitialImport ? "html-initial" : "html"
+  );
+}
+
+export var BookmarkHTMLUtils = Object.freeze({
+  /**
+   * Loads the current bookmarks hierarchy from a "bookmarks.html" file.
+   *
+   * @param aSpec
+   *        String containing the "file:" URI for the existing "bookmarks.html"
+   *        file to be loaded.
+   * @param [options.replace]
+   *        Whether we should erase existing bookmarks before loading.
+   *        Defaults to `false`.
+   * @param [options.source]
+   *        The bookmark change source, used to determine the sync status for
+   *        imported bookmarks. Defaults to `RESTORE` if `replace = true`, or
+   *        `IMPORT` otherwise.
+   *
+   * @return {Promise}
+   * @resolves When the new bookmarks have been created.
+   * @rejects JavaScript exception.
+   */
+  async importFromURL(
+    aSpec,
+    {
+      replace: aInitialImport = false,
+      source: aSource = aInitialImport
+        ? PlacesUtils.bookmarks.SOURCES.RESTORE
+        : PlacesUtils.bookmarks.SOURCES.IMPORT,
+    } = {}
+  ) {
+    notifyObservers(PlacesUtils.TOPIC_BOOKMARKS_RESTORE_BEGIN, aInitialImport);
+    try {
+      let importer = new BookmarkImporter(aInitialImport, aSource);
+      await importer.importFromURL(aSpec);
+
+      notifyObservers(
+        PlacesUtils.TOPIC_BOOKMARKS_RESTORE_SUCCESS,
+        aInitialImport
+      );
+    } catch (ex) {
+      console.error("Failed to import bookmarks from " + aSpec + ": " + ex);
+      notifyObservers(
+        PlacesUtils.TOPIC_BOOKMARKS_RESTORE_FAILED,
+        aInitialImport
+      );
+      throw ex;
+    }
+  },
+
+  /**
+   * Loads the current bookmarks hierarchy from a "bookmarks.html" file.
+   *
+   * @param aFilePath
+   *        OS.File path string of the "bookmarks.html" file to be loaded.
+   * @param [options.replace]
+   *        Whether we should erase existing bookmarks before loading.
+   *        Defaults to `false`.
+   * @param [options.source]
+   *        The bookmark change source, used to determine the sync status for
+   *        imported bookmarks. Defaults to `RESTORE` if `replace = true`, or
+   *        `IMPORT` otherwise.
+   *
+   * @return {Promise}
+   * @resolves When the new bookmarks have been created.
+   * @rejects JavaScript exception.
+   */
+  async importFromFile(
+    aFilePath,
+    {
+      replace: aInitialImport = false,
+      source: aSource = aInitialImport
+        ? PlacesUtils.bookmarks.SOURCES.RESTORE
+        : PlacesUtils.bookmarks.SOURCES.IMPORT,
+    } = {}
+  ) {
+    notifyObservers(PlacesUtils.TOPIC_BOOKMARKS_RESTORE_BEGIN, aInitialImport);
+    try {
+      if (!(await IOUtils.exists(aFilePath))) {
+        throw new Error(
+          "Cannot import from nonexisting html file: " + aFilePath
+        );
+      }
+      let importer = new BookmarkImporter(aInitialImport, aSource);
+      await importer.importFromURL(PathUtils.toFileURI(aFilePath));
+
+      notifyObservers(
+        PlacesUtils.TOPIC_BOOKMARKS_RESTORE_SUCCESS,
+        aInitialImport
+      );
+    } catch (ex) {
+      console.error("Failed to import bookmarks from " + aFilePath + ": " + ex);
+      notifyObservers(
+        PlacesUtils.TOPIC_BOOKMARKS_RESTORE_FAILED,
+        aInitialImport
+      );
+      throw ex;
+    }
+  },
+
+  /**
+   * Saves the current bookmarks hierarchy to a "bookmarks.html" file.
+   *
+   * @param aFilePath
+   *        OS.File path string for the "bookmarks.html" file to be created.
+   *
+   * @return {Promise}
+   * @resolves To the exported bookmarks count when the file has been created.
+   * @rejects JavaScript exception.
+   */
+  async exportToFile(aFilePath) {
+    let [bookmarks, count] = await lazy.PlacesBackups.getBookmarksTree();
+    let startTime = Date.now();
+
+    // Report the time taken to convert the tree to HTML.
+    let exporter = new BookmarkExporter(bookmarks);
+    await exporter.exportToFile(aFilePath);
+
+    try {
+      Services.telemetry
+        .getHistogramById("PLACES_EXPORT_TOHTML_MS")
+        .add(Date.now() - startTime);
+    } catch (ex) {
+      console.error("Unable to report telemetry.");
+    }
+
+    return count;
+  },
+
+  get defaultPath() {
+    try {
+      return Services.prefs.getCharPref("browser.bookmarks.file");
+    } catch (ex) {}
+    return PathUtils.join(PathUtils.profileDir, "bookmarks.html");
+  },
+});
+
+function Frame(aFolder) {
+  this.folder = aFolder;
+
+  /**
+   * How many <dl>s have been nested. Each frame/container should start
+   * with a heading, and is then followed by a <dl>, <ul>, or <menu>. When
+   * that list is complete, then it is the end of this container and we need
+   * to pop back up one level for new items. If we never get an open tag for
+   * one of these things, we should assume that the container is empty and
+   * that things we find should be siblings of it. Normally, these <dl>s won't
+   * be nested so this will be 0 or 1.
+   */
+  this.containerNesting = 0;
+
+  /**
+   * when we find a heading tag, it actually affects the title of the NEXT
+   * container in the list. This stores that heading tag and whether it was
+   * special. 'consumeHeading' resets this._
+   */
+  this.lastContainerType = Container_Normal;
+
+  /**
+   * this contains the text from the last begin tag until now. It is reset
+   * at every begin tag. We can check it when we see a </a>, or </h3>
+   * to see what the text content of that node should be.
+   */
+  this.previousText = "";
+
+  /**
+   * true when we hit a <dd>, which contains the description for the preceding
+   * <a> tag. We can't just check for </dd> like we can for </a> or </h3>
+   * because if there is a sub-folder, it is actually a child of the <dd>
+   * because the tag is never explicitly closed. If this is true and we see a
+   * new open tag, that means to commit the description to the previous
+   * bookmark.
+   *
+   * Additional weirdness happens when the previous <dt> tag contains a <h3>:
+   * this means there is a new folder with the given description, and whose
+   * children are contained in the following <dl> list.
+   *
+   * This is handled in openContainer(), which commits previous text if
+   * necessary.
+   */
+  this.inDescription = false;
+
+  /**
+   * contains the URL of the previous bookmark created. This is used so that
+   * when we encounter a <dd>, we know what bookmark to associate the text with.
+   * This is cleared whenever we hit a <h3>, so that we know NOT to save this
+   * with a bookmark, but to keep it until
+   */
+  this.previousLink = null;
+
+  /**
+   * Contains a reference to the last created bookmark or folder object.
+   */
+  this.previousItem = null;
+
+  /**
+   * Contains the date-added and last-modified-date of an imported item.
+   * Used to override the values set by insertBookmark, createFolder, etc.
+   */
+  this.previousDateAdded = null;
+  this.previousLastModifiedDate = null;
+}
+
+function BookmarkImporter(aInitialImport, aSource) {
+  this._isImportDefaults = aInitialImport;
+  this._source = aSource;
+
+  // This root is where we construct the bookmarks tree into, following the format
+  // of the imported file.
+  // If we're doing an initial import, the non-menu roots will be created as
+  // children of this root, so in _getBookmarkTrees we'll split them out.
+  // If we're not doing an initial import, everything gets imported under the
+  // bookmark menu folder, so there won't be any need for _getBookmarkTrees to
+  // do separation.
+  this._bookmarkTree = {
+    type: PlacesUtils.bookmarks.TYPE_FOLDER,
+    guid: PlacesUtils.bookmarks.menuGuid,
+    children: [],
+  };
+
+  this._frames = [];
+  this._frames.push(new Frame(this._bookmarkTree));
+}
+
+BookmarkImporter.prototype = {
+  _safeTrim: function safeTrim(aStr) {
+    return aStr ? aStr.trim() : aStr;
+  },
+
+  get _curFrame() {
+    return this._frames[this._frames.length - 1];
+  },
+
+  get _previousFrame() {
+    return this._frames[this._frames.length - 2];
+  },
+
+  /**
+   * This is called when there is a new folder found. The folder takes the
+   * name from the previous frame's heading.
+   */
+  _newFrame: function newFrame() {
+    let frame = this._curFrame;
+    let containerTitle = frame.previousText;
+    frame.previousText = "";
+    let containerType = frame.lastContainerType;
+
+    let folder = {
+      children: [],
+      type: PlacesUtils.bookmarks.TYPE_FOLDER,
+    };
+
+    switch (containerType) {
+      case Container_Normal:
+        // This can only be a sub-folder so no need to set a guid here.
+        folder.title = containerTitle;
+        break;
+      case Container_Places:
+        folder.guid = PlacesUtils.bookmarks.rootGuid;
+        break;
+      case Container_Menu:
+        folder.guid = PlacesUtils.bookmarks.menuGuid;
+        break;
+      case Container_Unfiled:
+        folder.guid = PlacesUtils.bookmarks.unfiledGuid;
+        break;
+      case Container_Toolbar:
+        folder.guid = PlacesUtils.bookmarks.toolbarGuid;
+        break;
+      default:
+        // NOT REACHED
+        throw new Error("Unknown bookmark container type!");
+    }
+
+    frame.folder.children.push(folder);
+
+    if (frame.previousDateAdded != null) {
+      folder.dateAdded = frame.previousDateAdded;
+      frame.previousDateAdded = null;
+    }
+
+    if (frame.previousLastModifiedDate != null) {
+      folder.lastModified = frame.previousLastModifiedDate;
+      frame.previousLastModifiedDate = null;
+    }
+
+    if (
+      !folder.hasOwnProperty("dateAdded") &&
+      folder.hasOwnProperty("lastModified")
+    ) {
+      folder.dateAdded = folder.lastModified;
+    }
+
+    frame.previousItem = folder;
+
+    this._frames.push(new Frame(folder));
+  },
+
+  /**
+   * Handles <hr> as a separator.
+   *
+   * @note Separators may have a title in old html files, though Places dropped
+   *       support for them.
+   *       We also don't import ADD_DATE or LAST_MODIFIED for separators because
+   *       pre-Places bookmarks did not support them.
+   */
+  _handleSeparator: function handleSeparator(aElt) {
+    let frame = this._curFrame;
+
+    let separator = {
+      type: PlacesUtils.bookmarks.TYPE_SEPARATOR,
+    };
+    frame.folder.children.push(separator);
+    frame.previousItem = separator;
+  },
+
+  /**
+   * Called for h2,h3,h4,h5,h6. This just stores the correct information in
+   * the current frame; the actual new frame corresponding to the container
+   * associated with the heading will be created when the tag has been closed
+   * and we know the title (we don't know to create a new folder or to merge
+   * with an existing one until we have the title).
+   */
+  _handleHeadBegin: function handleHeadBegin(aElt) {
+    let frame = this._curFrame;
+
+    // after a heading, a previous bookmark is not applicable (for example, for
+    // the descriptions contained in a <dd>). Neither is any previous head type
+    frame.previousLink = null;
+    frame.lastContainerType = Container_Normal;
+
+    // It is syntactically possible for a heading to appear after another heading
+    // but before the <dl> that encloses that folder's contents.  This should not
+    // happen in practice, as the file will contain "<dl></dl>" sequence for
+    // empty containers.
+    //
+    // Just to be on the safe side, if we encounter
+    //   <h3>FOO</h3>
+    //   <h3>BAR</h3>
+    //   <dl>...content 1...</dl>
+    //   <dl>...content 2...</dl>
+    // we'll pop the stack when we find the h3 for BAR, treating that as an
+    // implicit ending of the FOO container. The output will be FOO and BAR as
+    // siblings. If there's another <dl> following (as in "content 2"), those
+    // items will be treated as further siblings of FOO and BAR
+    // This special frame popping business, of course, only happens when our
+    // frame array has more than one element so we can avoid situations where
+    // we don't have a frame to parse into anymore.
+    if (frame.containerNesting == 0 && this._frames.length > 1) {
+      this._frames.pop();
+    }
+
+    // We have to check for some attributes to see if this is a "special"
+    // folder, which will have different creation rules when the end tag is
+    // processed.
+    if (aElt.hasAttribute("personal_toolbar_folder")) {
+      if (this._isImportDefaults) {
+        frame.lastContainerType = Container_Toolbar;
+      }
+    } else if (aElt.hasAttribute("bookmarks_menu")) {
+      if (this._isImportDefaults) {
+        frame.lastContainerType = Container_Menu;
+      }
+    } else if (aElt.hasAttribute("unfiled_bookmarks_folder")) {
+      if (this._isImportDefaults) {
+        frame.lastContainerType = Container_Unfiled;
+      }
+    } else if (aElt.hasAttribute("places_root")) {
+      if (this._isImportDefaults) {
+        frame.lastContainerType = Container_Places;
+      }
+    } else {
+      let addDate = aElt.getAttribute("add_date");
+      if (addDate) {
+        frame.previousDateAdded = this._convertImportedDateToInternalDate(
+          addDate
+        );
+      }
+      let modDate = aElt.getAttribute("last_modified");
+      if (modDate) {
+        frame.previousLastModifiedDate = this._convertImportedDateToInternalDate(
+          modDate
+        );
+      }
+    }
+    this._curFrame.previousText = "";
+  },
+
+  /*
+   * Handles "<a" tags by creating a new bookmark. The title of the bookmark
+   * will be the text content, which will be stuffed in previousText for us
+   * and which will be saved by handleLinkEnd
+   */
+  _handleLinkBegin: function handleLinkBegin(aElt) {
+    let frame = this._curFrame;
+
+    frame.previousItem = null;
+    frame.previousText = ""; // Will hold link text, clear it.
+
+    // Get the attributes we care about.
+    let href = this._safeTrim(aElt.getAttribute("href"));
+    let icon = this._safeTrim(aElt.getAttribute("icon"));
+    let iconUri = this._safeTrim(aElt.getAttribute("icon_uri"));
+    let lastCharset = this._safeTrim(aElt.getAttribute("last_charset"));
+    let keyword = this._safeTrim(aElt.getAttribute("shortcuturl"));
+    let postData = this._safeTrim(aElt.getAttribute("post_data"));
+    let dateAdded = this._safeTrim(aElt.getAttribute("add_date"));
+    let lastModified = this._safeTrim(aElt.getAttribute("last_modified"));
+    let tags = this._safeTrim(aElt.getAttribute("tags"));
+
+    // Ignore <a> tags that have no href.
+    try {
+      frame.previousLink = Services.io.newURI(href).spec;
+    } catch (e) {
+      frame.previousLink = null;
+      return;
+    }
+
+    let bookmark = {};
+
+    // Only set the url for bookmarks.
+    if (frame.previousLink) {
+      bookmark.url = frame.previousLink;
+    }
+
+    if (dateAdded) {
+      bookmark.dateAdded = this._convertImportedDateToInternalDate(dateAdded);
+    }
+    // Save bookmark's last modified date.
+    if (lastModified) {
+      bookmark.lastModified = this._convertImportedDateToInternalDate(
+        lastModified
+      );
+    }
+
+    if (!dateAdded && lastModified) {
+      bookmark.dateAdded = bookmark.lastModified;
+    }
+
+    if (tags) {
+      bookmark.tags = tags
+        .split(",")
+        .filter(
+          aTag =>
+            !!aTag.length && aTag.length <= PlacesUtils.bookmarks.MAX_TAG_LENGTH
+        );
+
+      // If we end up with none, then delete the property completely.
+      if (!bookmark.tags.length) {
+        delete bookmark.tags;
+      }
+    }
+
+    if (lastCharset) {
+      bookmark.charset = lastCharset;
+    }
+
+    if (keyword) {
+      bookmark.keyword = keyword;
+    }
+
+    if (postData) {
+      bookmark.postData = postData;
+    }
+
+    if (icon) {
+      bookmark.icon = icon;
+    }
+
+    if (iconUri) {
+      bookmark.iconUri = iconUri;
+    }
+
+    // Add bookmark to the tree.
+    frame.folder.children.push(bookmark);
+    frame.previousItem = bookmark;
+  },
+
+  _handleContainerBegin: function handleContainerBegin() {
+    this._curFrame.containerNesting++;
+  },
+
+  /**
+   * Our "indent" count has decreased, and when we hit 0 that means that this
+   * container is complete and we need to pop back to the outer frame. Never
+   * pop the toplevel frame
+   */
+  _handleContainerEnd: function handleContainerEnd() {
+    let frame = this._curFrame;
+    if (frame.containerNesting > 0) {
+      frame.containerNesting--;
+    }
+    if (this._frames.length > 1 && frame.containerNesting == 0) {
+      this._frames.pop();
+    }
+  },
+
+  /**
+   * Creates the new frame for this heading now that we know the name of the
+   * container (tokens since the heading open tag will have been placed in
+   * previousText).
+   */
+  _handleHeadEnd: function handleHeadEnd() {
+    this._newFrame();
+  },
+
+  /**
+   * Saves the title for the given bookmark.
+   */
+  _handleLinkEnd: function handleLinkEnd() {
+    let frame = this._curFrame;
+    frame.previousText = frame.previousText.trim();
+
+    if (frame.previousItem != null) {
+      frame.previousItem.title = frame.previousText;
+    }
+
+    frame.previousText = "";
+  },
+
+  _openContainer: function openContainer(aElt) {
+    if (aElt.namespaceURI != "http://www.w3.org/1999/xhtml") {
+      return;
+    }
+    switch (aElt.localName) {
+      case "h2":
+      case "h3":
+      case "h4":
+      case "h5":
+      case "h6":
+        this._handleHeadBegin(aElt);
+        break;
+      case "a":
+        this._handleLinkBegin(aElt);
+        break;
+      case "dl":
+      case "ul":
+      case "menu":
+        this._handleContainerBegin();
+        break;
+      case "dd":
+        this._curFrame.inDescription = true;
+        break;
+      case "hr":
+        this._handleSeparator(aElt);
+        break;
+    }
+  },
+
+  _closeContainer: function closeContainer(aElt) {
+    let frame = this._curFrame;
+
+    // Although we no longer support importing descriptions, we still need to
+    // clear any previous text, so that it doesn't get swallowed into other elements.
+    if (frame.inDescription) {
+      frame.previousText = "";
+      frame.inDescription = false;
+    }
+
+    if (aElt.namespaceURI != "http://www.w3.org/1999/xhtml") {
+      return;
+    }
+    switch (aElt.localName) {
+      case "dl":
+      case "ul":
+      case "menu":
+        this._handleContainerEnd();
+        break;
+      case "dt":
+        break;
+      case "h1":
+        // ignore
+        break;
+      case "h2":
+      case "h3":
+      case "h4":
+      case "h5":
+      case "h6":
+        this._handleHeadEnd();
+        break;
+      case "a":
+        this._handleLinkEnd();
+        break;
+      default:
+        break;
+    }
+  },
+
+  _appendText: function appendText(str) {
+    this._curFrame.previousText += str;
+  },
+
+  /**
+   * Converts a string date in seconds to a date object
+   */
+  _convertImportedDateToInternalDate: function convertImportedDateToInternalDate(
+    aDate
+  ) {
+    try {
+      if (aDate && !isNaN(aDate)) {
+        return new Date(parseInt(aDate) * 1000); // in bookmarks.html this value is in seconds
+      }
+    } catch (ex) {
+      // Do nothing.
+    }
+    return new Date();
+  },
+
+  _walkTreeForImport(aDoc) {
+    if (!aDoc) {
+      return;
+    }
+
+    let current = aDoc;
+    let next;
+    for (;;) {
+      switch (current.nodeType) {
+        case current.ELEMENT_NODE:
+          this._openContainer(current);
+          break;
+        case current.TEXT_NODE:
+          this._appendText(current.data);
+          break;
+      }
+      if ((next = current.firstChild)) {
+        current = next;
+        continue;
+      }
+      for (;;) {
+        if (current.nodeType == current.ELEMENT_NODE) {
+          this._closeContainer(current);
+        }
+        if (current == aDoc) {
+          return;
+        }
+        if ((next = current.nextSibling)) {
+          current = next;
+          break;
+        }
+        current = current.parentNode;
+      }
+    }
+  },
+
+  /**
+   * Returns the bookmark tree(s) from the importer. These are suitable for
+   * passing to PlacesUtils.bookmarks.insertTree().
+   *
+   * @returns {Array} An array of bookmark trees.
+   */
+  _getBookmarkTrees() {
+    // If we're not importing defaults, then everything gets imported under the
+    // Bookmarks menu.
+    if (!this._isImportDefaults) {
+      return [this._bookmarkTree];
+    }
+
+    // If we are importing defaults, we need to separate out the top-level
+    // default folders into separate items, for the caller to pass into insertTree.
+    let bookmarkTrees = [this._bookmarkTree];
+
+    // The children of this "root" element will contain normal children of the
+    // bookmark menu as well as the places roots. Hence, we need to filter out
+    // the separate roots, but keep the children that are relevant to the
+    // bookmark menu.
+    this._bookmarkTree.children = this._bookmarkTree.children.filter(child => {
+      if (
+        child.guid &&
+        PlacesUtils.bookmarks.userContentRoots.includes(child.guid)
+      ) {
+        bookmarkTrees.push(child);
+        return false;
+      }
+      return true;
+    });
+
+    return bookmarkTrees;
+  },
+
+  /**
+   * Imports the bookmarks from the importer into the places database.
+   *
+   * @param {BookmarkImporter} importer The importer from which to get the
+   *                                    bookmark information.
+   */
+  async _importBookmarks() {
+    if (this._isImportDefaults) {
+      await PlacesUtils.bookmarks.eraseEverything();
+    }
+
+    let bookmarksTrees = this._getBookmarkTrees();
+    for (let tree of bookmarksTrees) {
+      if (!tree.children.length) {
+        continue;
+      }
+
+      // Give the tree the source.
+      tree.source = this._source;
+      await PlacesUtils.bookmarks.insertTree(tree, {
+        fixupOrSkipInvalidEntries: true,
+      });
+      insertFaviconsForTree(tree);
+    }
+  },
+
+  /**
+   * Imports data into the places database from the supplied url.
+   *
+   * @param {String} href The url to import data from.
+   */
+  async importFromURL(href) {
+    let data = await fetchData(href);
+
+    if (this._isImportDefaults && data) {
+      // Localize default bookmarks.  Find rel="localization" links and manually
+      // localize using them.
+      let hrefs = [];
+      let links = data.head.querySelectorAll("link[rel='localization']");
+      for (let link of links) {
+        if (link.getAttribute("href")) {
+          // We need the text, not the fully qualified URL, so we use `getAttribute`.
+          hrefs.push(link.getAttribute("href"));
+        }
+      }
+
+      if (hrefs.length) {
+        let domLoc = new DOMLocalization(hrefs);
+        await domLoc.translateFragment(data.body);
+      }
+    }
+
+    this._walkTreeForImport(data);
+    await this._importBookmarks();
+  },
+};
+
+function BookmarkExporter(aBookmarksTree) {
+  // Create a map of the roots.
+  let rootsMap = new Map();
+  for (let child of aBookmarksTree.children) {
+    if (child.root) {
+      rootsMap.set(child.root, child);
+      // Also take the opportunity to get the correctly localised title for the
+      // root.
+      child.title = PlacesUtils.bookmarks.getLocalizedTitle(child);
+    }
+  }
+
+  // For backwards compatibility reasons the bookmarks menu is the root, while
+  // the bookmarks toolbar and unfiled bookmarks will be child items.
+  this._root = rootsMap.get("bookmarksMenuFolder");
+
+  for (let key of ["toolbarFolder", "unfiledBookmarksFolder"]) {
+    let root = rootsMap.get(key);
+    if (root.children && root.children.length) {
+      if (!this._root.children) {
+        this._root.children = [];
+      }
+      this._root.children.push(root);
+    }
+  }
+}
+
+BookmarkExporter.prototype = {
+  exportToFile: function exportToFile(aFilePath) {
+    return (async () => {
+      // Create a file that can be accessed by the current user only.
+      let out = FileUtils.openAtomicFileOutputStream(
+        new FileUtils.File(aFilePath)
+      );
+      try {
+        // We need a buffered output stream for performance.  See bug 202477.
+        let bufferedOut = Cc[
+          "@mozilla.org/network/buffered-output-stream;1"
+        ].createInstance(Ci.nsIBufferedOutputStream);
+        bufferedOut.init(out, 4096);
+        try {
+          // Write bookmarks in UTF-8.
+          this._converterOut = Cc[
+            "@mozilla.org/intl/converter-output-stream;1"
+          ].createInstance(Ci.nsIConverterOutputStream);
+          this._converterOut.init(bufferedOut, "utf-8");
+          try {
+            this._writeHeader();
+            await this._writeContainer(this._root);
+            // Retain the target file on success only.
+            bufferedOut.QueryInterface(Ci.nsISafeOutputStream).finish();
+          } finally {
+            this._converterOut.close();
+            this._converterOut = null;
+          }
+        } finally {
+          bufferedOut.close();
+        }
+      } finally {
+        out.close();
+      }
+    })();
+  },
+
+  _converterOut: null,
+
+  _write(aText) {
+    this._converterOut.writeString(aText || "");
+  },
+
+  _writeAttribute(aName, aValue) {
+    this._write(" " + aName + '="' + aValue + '"');
+  },
+
+  _writeLine(aText) {
+    this._write(aText + "\n");
+  },
+
+  _writeHeader() {
+    this._writeLine("<!DOCTYPE NETSCAPE-Bookmark-file-1>");
+    this._writeLine("<!-- This is an automatically generated file.");
+    this._writeLine("     It will be read and overwritten.");
+    this._writeLine("     DO NOT EDIT! -->");
+    this._writeLine(
+      '<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=UTF-8">'
+    );
+    this._writeLine(`<meta http-equiv="Content-Security-Policy"
+      content="default-src 'self'; script-src 'none'; img-src data: *; object-src 'none'"></meta>`);
+    this._writeLine("<TITLE>Bookmarks</TITLE>");
+  },
+
+  async _writeContainer(aItem, aIndent = "") {
+    if (aItem == this._root) {
+      this._writeLine("<H1>" + escapeHtmlEntities(this._root.title) + "</H1>");
+      this._writeLine("");
+    } else {
+      this._write(aIndent + "<DT><H3");
+      this._writeDateAttributes(aItem);
+
+      if (aItem.root === "toolbarFolder") {
+        this._writeAttribute("PERSONAL_TOOLBAR_FOLDER", "true");
+      } else if (aItem.root === "unfiledBookmarksFolder") {
+        this._writeAttribute("UNFILED_BOOKMARKS_FOLDER", "true");
+      }
+      this._writeLine(">" + escapeHtmlEntities(aItem.title) + "</H3>");
+    }
+
+    this._writeLine(aIndent + "<DL><p>");
+    if (aItem.children) {
+      await this._writeContainerContents(aItem, aIndent);
+    }
+    if (aItem == this._root) {
+      this._writeLine(aIndent + "</DL>");
+    } else {
+      this._writeLine(aIndent + "</DL><p>");
+    }
+  },
+
+  async _writeContainerContents(aItem, aIndent) {
+    let localIndent = aIndent + EXPORT_INDENT;
+
+    for (let child of aItem.children) {
+      if (child.type == PlacesUtils.TYPE_X_MOZ_PLACE_CONTAINER) {
+        await this._writeContainer(child, localIndent);
+      } else if (child.type == PlacesUtils.TYPE_X_MOZ_PLACE_SEPARATOR) {
+        this._writeSeparator(child, localIndent);
+      } else {
+        await this._writeItem(child, localIndent);
+      }
+    }
+  },
+
+  _writeSeparator(aItem, aIndent) {
+    this._write(aIndent + "<HR");
+    // We keep exporting separator titles, but don't support them anymore.
+    if (aItem.title) {
+      this._writeAttribute("NAME", escapeHtmlEntities(aItem.title));
+    }
+    this._write(">");
+  },
+
+  async _writeItem(aItem, aIndent) {
+    try {
+      NetUtil.newURI(aItem.uri);
+    } catch (ex) {
+      // If the item URI is invalid, skip the item instead of failing later.
+      return;
+    }
+
+    this._write(aIndent + "<DT><A");
+    this._writeAttribute("HREF", escapeUrl(aItem.uri));
+    this._writeDateAttributes(aItem);
+    await this._writeFaviconAttribute(aItem);
+
+    if (aItem.keyword) {
+      this._writeAttribute("SHORTCUTURL", escapeHtmlEntities(aItem.keyword));
+      if (aItem.postData) {
+        this._writeAttribute("POST_DATA", escapeHtmlEntities(aItem.postData));
+      }
+    }
+
+    if (aItem.charset) {
+      this._writeAttribute("LAST_CHARSET", escapeHtmlEntities(aItem.charset));
+    }
+    if (aItem.tags) {
+      this._writeAttribute("TAGS", escapeHtmlEntities(aItem.tags));
+    }
+    this._writeLine(">" + escapeHtmlEntities(aItem.title) + "</A>");
+  },
+
+  _writeDateAttributes(aItem) {
+    if (aItem.dateAdded) {
+      this._writeAttribute(
+        "ADD_DATE",
+        Math.floor(aItem.dateAdded / MICROSEC_PER_SEC)
+      );
+    }
+    if (aItem.lastModified) {
+      this._writeAttribute(
+        "LAST_MODIFIED",
+        Math.floor(aItem.lastModified / MICROSEC_PER_SEC)
+      );
+    }
+  },
+
+  async _writeFaviconAttribute(aItem) {
+    if (!aItem.iconUri) {
+      return;
+    }
+    let favicon;
+    try {
+      favicon = await PlacesUtils.promiseFaviconData(aItem.uri);
+    } catch (ex) {
+      console.error("Unexpected Error trying to fetch icon data");
+      return;
+    }
+
+    this._writeAttribute("ICON_URI", escapeUrl(favicon.uri.spec));
+
+    if (!favicon.uri.schemeIs("chrome") && favicon.dataLen > 0) {
+      let faviconContents =
+        "data:image/png;base64," +
+        base64EncodeString(String.fromCharCode.apply(String, favicon.data));
+      this._writeAttribute("ICON", faviconContents);
+    }
+  },
+};
+
+/**
+ * Handles inserting favicons into the database for a bookmark node.
+ * It is assumed the node has already been inserted into the bookmarks
+ * database.
+ *
+ * @param {Object} node The bookmark node for icons to be inserted.
+ */
+function insertFaviconForNode(node) {
+  if (node.icon) {
+    try {
+      // Create a fake faviconURI to use (FIXME: bug 523932)
+      let faviconURI = Services.io.newURI("fake-favicon-uri:" + node.url);
+      PlacesUtils.favicons.replaceFaviconDataFromDataURL(
+        faviconURI,
+        node.icon,
+        0,
+        Services.scriptSecurityManager.getSystemPrincipal()
+      );
+      PlacesUtils.favicons.setAndFetchFaviconForPage(
+        Services.io.newURI(node.url),
+        faviconURI,
+        false,
+        PlacesUtils.favicons.FAVICON_LOAD_NON_PRIVATE,
+        null,
+        Services.scriptSecurityManager.getSystemPrincipal()
+      );
+    } catch (ex) {
+      console.error("Failed to import favicon data:" + ex);
+    }
+  }
+
+  if (!node.iconUri) {
+    return;
+  }
+
+  try {
+    PlacesUtils.favicons.setAndFetchFaviconForPage(
+      Services.io.newURI(node.url),
+      Services.io.newURI(node.iconUri),
+      false,
+      PlacesUtils.favicons.FAVICON_LOAD_NON_PRIVATE,
+      null,
+      Services.scriptSecurityManager.getSystemPrincipal()
+    );
+  } catch (ex) {
+    console.error("Failed to import favicon URI:" + ex);
+  }
+}
+
+/**
+ * Handles inserting favicons into the database for a bookmark tree - a node
+ * and its children.
+ *
+ * It is assumed the nodes have already been inserted into the bookmarks
+ * database.
+ *
+ * @param {Object} nodeTree The bookmark node tree for icons to be inserted.
+ */
+function insertFaviconsForTree(nodeTree) {
+  insertFaviconForNode(nodeTree);
+
+  if (nodeTree.children) {
+    for (let child of nodeTree.children) {
+      insertFaviconsForTree(child);
+    }
+  }
+}
+
+/**
+ * Handles fetching data from a URL.
+ *
+ * @param {String} href The url to fetch data from.
+ * @return {Promise} Returns a promise that is resolved with the data once
+ *                   the fetch is complete, or is rejected if it fails.
+ */
+function fetchData(href) {
+  return new Promise((resolve, reject) => {
+    let xhr = new XMLHttpRequest();
+    xhr.onload = () => {
+      resolve(xhr.responseXML);
+    };
+    xhr.onabort = xhr.onerror = xhr.ontimeout = () => {
+      reject(new Error("xmlhttprequest failed"));
+    };
+    xhr.open("GET", href);
+    xhr.responseType = "document";
+    xhr.overrideMimeType("text/html");
+    xhr.send();
+  });
+}