2 files changed, 29 insertions, 39 deletions

diff --git a/application/palemoon/components/downloads/DownloadsCommon.jsm b/application/palemoon/components/downloads/DownloadsCommon.jsm
index 2bfd7b528..aac43d197 100644
--- a/application/palemoon/components/downloads/DownloadsCommon.jsm
+++ b/application/palemoon/components/downloads/DownloadsCommon.jsm
@@ -647,12 +647,8 @@ XPCOMUtils.defineLazyGetter(DownloadsCommon, "useJSTransfer", function () {
 function DownloadsDataCtor(aPrivate) {
   this._isPrivate = aPrivate;
 
-  // This Object contains all the available DownloadsDataItem objects, indexed by
-  // their globally unique identifier.  The identifiers of downloads that have
-  // been removed from the Download Manager data are still present, however the
-  // associated objects are replaced with the value "null".  This is required to
-  // prevent race conditions when populating the list asynchronously.
-  this.dataItems = {};
+  // Contains all the available DownloadsDataItem objects.
+  this.dataItems = new Set();
 
   // Array of view objects that should be notified when the available download
   // data changes.
@@ -690,8 +686,8 @@ DownloadsDataCtor.prototype = {
    */
   get canRemoveFinished()
   {
-    for (let [, dataItem] of Iterator(this.dataItems)) {
-      if (dataItem && !dataItem.inProgress) {
+    for (let dataItem of this.dataItems) {
+      if (!dataItem.inProgress) {
         return true;
       }
     }
@@ -716,7 +712,7 @@ DownloadsDataCtor.prototype = {
   {
     let dataItem = new DownloadsDataItem(aDownload);
     this._downloadToDataItemMap.set(aDownload, dataItem);
-    this.dataItems[dataItem.downloadGuid] = dataItem;
+    this.dataItems.add(dataItem);
 
     for (let view of this._views) {
       view.onDataItemAdded(dataItem, true);
@@ -745,7 +741,7 @@ DownloadsDataCtor.prototype = {
     }
 
     this._downloadToDataItemMap.delete(aDownload);
-    this.dataItems[dataItem.downloadGuid] = null;
+    this.dataItems.delete(dataItem);
     for (let view of this._views) {
       view.onDataItemRemoved(dataItem);
     }
@@ -861,14 +857,7 @@ DownloadsDataCtor.prototype = {
     //let loadedItemsArray = [dataItem
     //                        for each (dataItem in this.dataItems)
     //                        if (dataItem)];
-
-    let loadedItemsArray = [];
-
-    for each (let dataItem in this.dataItems) {
-      if (dataItem) {
-        loadedItemsArray.push(dataItem);
-      }
-    }
+    let loadedItemsArray = [...this.dataItems];
 
     loadedItemsArray.sort(function(a, b) b.download.startTime - a.download.startTime);
     loadedItemsArray.forEach(
@@ -1345,13 +1334,6 @@ function DownloadsDataItem(aSource)
 
 DownloadsDataItem.prototype = {
   /**
-   * The JavaScript API does not need identifiers for Download objects, so they
-   * are generated sequentially for the corresponding DownloadDataItem.
-   */
-  get _autoIncrementId() ++DownloadsDataItem.prototype.__lastId,
-  __lastId: 0,
-
-  /**
    * Initializes this object from the JavaScript API for downloads.
    *
    * The endTime property is initialized to the current date and time.
@@ -1362,8 +1344,6 @@ DownloadsDataItem.prototype = {
   _initFromJSDownload: function (aDownload)
   {
     this.download = aDownload;
-
-    this.downloadGuid = "id:" + this._autoIncrementId;
     this.endTime = Date.now();
 
     this.updateFromJSDownload();
@@ -2029,7 +2009,7 @@ DownloadsIndicatorDataCtor.prototype = {
   {
     let dataItems = this._isPrivate ? PrivateDownloadsData.dataItems
                                     : DownloadsData.dataItems;
-    for each (let dataItem in dataItems) {
+    for (let dataItem of dataItems) {
       if (dataItem && dataItem.inProgress) {
         yield dataItem;
       }
diff --git a/application/palemoon/components/downloads/content/downloads.js b/application/palemoon/components/downloads/content/downloads.js
index af0c85535..a6c716b8c 100644
--- a/application/palemoon/components/downloads/content/downloads.js
+++ b/application/palemoon/components/downloads/content/downloads.js
@@ -896,6 +896,16 @@ const DownloadsView = {
   },
 
   /**
+   * Associates each richlistitem for a download with its corresponding
+   * DownloadsViewItemController object.
+   */
+  _controllersForElements: new Map(),
+
+  controllerForElement(element) {
+    return this._controllersForElements.get(element);
+  },
+
+  /**
    * Creates a new view item associated with the specified data item, and adds
    * it to the top or the bottom of the list.
    */
@@ -907,6 +917,8 @@ const DownloadsView = {
     let element = document.createElement("richlistitem");
     let viewItem = new DownloadsViewItem(aDataItem, element);
     this._visibleViewItems.set(aDataItem, viewItem);
+    let viewItemController = new DownloadsViewItemController(aDataItem);
+    this._controllersForElements.set(element, viewItemController);
     if (aNewest) {
       this.richListBox.insertBefore(element, this.richListBox.firstChild);
     } else {
@@ -928,6 +940,7 @@ const DownloadsView = {
                                                 this.richListBox.itemCount - 1);
     }
     this._visibleViewItems.delete(aDataItem);
+    this._controllersForElements.delete(element);
   },
 
   //////////////////////////////////////////////////////////////////////////////
@@ -949,7 +962,7 @@ const DownloadsView = {
     while (target.nodeName != "richlistitem") {
       target = target.parentNode;
     }
-    new DownloadsViewItemController(target).doCommand(aCommand);
+    DownloadsView.controllerForElement(target).doCommand(aCommand);
   },
 
   onDownloadClick: function DV_onDownloadClick(aEvent)
@@ -1028,8 +1041,8 @@ const DownloadsView = {
       return;
     }
 
-    let controller = new DownloadsViewItemController(element);
-    let localFile = controller.dataItem.localFile;
+    let localFile = DownloadsView.controllerForElement(element)
+                                 .dataItem.localFile;
     if (!localFile.exists()) {
       return;
     }
@@ -1082,8 +1095,6 @@ function DownloadsViewItem(aDataItem, aElement)
   let attributes = {
     "type": "download",
     "class": "download-state",
-    "id": "downloadsItem_" + this.dataItem.downloadGuid,
-    "downloadGuid": this.dataItem.downloadGuid,
     "state": this.dataItem.state,
     "progress": this.dataItem.inProgress ? this.dataItem.percentComplete : 100,
     "displayName": target,
@@ -1360,8 +1371,8 @@ const DownloadsViewController = {
 
     // Other commands are selection-specific.
     let element = DownloadsView.richListBox.selectedItem;
-    return element &&
-           new DownloadsViewItemController(element).isCommandEnabled(aCommand);
+    return element && DownloadsView.controllerForElement(element)
+                                   .isCommandEnabled(aCommand);
   },
 
   doCommand: function DVC_doCommand(aCommand)
@@ -1376,7 +1387,7 @@ const DownloadsViewController = {
     let element = DownloadsView.richListBox.selectedItem;
     if (element) {
       // The doCommand function also checks if the command is enabled.
-      new DownloadsViewItemController(element).doCommand(aCommand);
+      DownloadsView.controllerForElement(element).doCommand(aCommand);
     }
   },
 
@@ -1416,9 +1427,8 @@ XPCOMUtils.defineConstant(this, "DownloadsViewController", DownloadsViewControll
  * Handles all the user interaction events, in particular the "commands",
  * related to a single item in the downloads list widgets.
  */
-function DownloadsViewItemController(aElement) {
-  let downloadGuid = aElement.getAttribute("downloadGuid");
-  this.dataItem = DownloadsCommon.getData(window).dataItems[downloadGuid];
+function DownloadsViewItemController(aDataItem) {
+  this.dataItem = aDataItem;
 }
 
 DownloadsViewItemController.prototype = {