Fixed alias plugin preventing operations on the original plugin

When alias plugin is initialised it also initialises it's children.
If the alias plugin is on the same page as the plugin that is being
aliased this leads to the event handlers bound twice. So if you
try to toggle context menu or nested plugins in structure mode the
operation would be ran twice and would technically fail. This
commit stops initialisation of the plugin that already has been
initialised.

Essentially this is a backport of changes from django-cms#5429
Ref: django-cms#5382

CHANGELOG.txt

@@ -34,6 +34,8 @@
   page tree dropdowns.
 * Fixed a bug where Django Compressor could not be used on the sekizai ``js``
   block.
+* Fixed an issue when plugin that is aliased on the same page couldn't be
+  operated upon in the structure mode.
 
 
 === 3.3.0 (2016-05-26) ===

cms/static/cms/js/modules/cms.plugins.js

@@ -67,6 +67,9 @@ var Plugin = new Class({
 
         // bind data element to the container
         this.ui.container.data('settings', this.options);
+        if (Plugin.aliasPluginDuplicatesMap[this.options.plugin_id]) {
+            return;
+        }
         Plugin._initializeDragItemsStates();
 
         // determine type of plugin
@@ -76,6 +79,7 @@ var Plugin = new Class({
                 this._collapsables();
                 break;
             case 'plugin': // handler for all plugins
+                Plugin.aliasPluginDuplicatesMap[this.options.plugin_id] = true;
                 this._setPlugin();
                 this._collapsables();
                 break;
@@ -1645,6 +1649,8 @@ Plugin._initializeDragItemsStates = Helpers.once(function _initializeDragItemsSt
     });
 });
 
+Plugin.aliasPluginDuplicatesMap = {};
+
 // shorthand for jQuery(document).ready();
 $(Plugin._initializeGlobalHandlers);
 

cms/tests/frontend/unit/cms.plugins.test.js

@@ -39,6 +39,10 @@ describe('CMS.Plugin', function () {
         });
     });
 
+    afterEach(function () {
+        Plugin.aliasPluginDuplicatesMap = {};
+    });
+
     describe('instance', function () {
         var plugin1;
         var plugin2;
@@ -244,8 +248,35 @@ describe('CMS.Plugin', function () {
             expect(generic.ui.container.data('settings')).toEqual(generic.options);
         });
 
+        it('doesnt reset the ui if the same plugin is initialized twice (alias case)', function () {
+            spyOn(Plugin.prototype, '_setPlugin');
+            spyOn(Plugin.prototype, '_setPlaceholder');
+            spyOn(Plugin.prototype, '_setGeneric');
+            expect(Plugin.aliasPluginDuplicatesMap[plugin1.options.plugin_id]).toEqual(true);
+
+            new CMS.Plugin('cms-plugin-1', {
+                type: 'plugin',
+                plugin_id: 1,
+                plugin_type: 'TextPlugin',
+                placeholder_id: 1,
+                urls: {
+                    add_plugin: '/en/admin/cms/page/add-plugin/',
+                    edit_plugin: '/en/admin/cms/page/edit-plugin/1/',
+                    move_plugin: '/en/admin/cms/page/move-plugin/',
+                    delete_plugin: '/en/admin/cms/page/delete-plugin/1/',
+                    copy_plugin: '/en/admin/cms/page/copy-plugins/'
+                }
+            });
+
+            expect(Plugin.aliasPluginDuplicatesMap[plugin1.options.plugin_id]).toEqual(true);
+            expect(Plugin.prototype._setPlugin).not.toHaveBeenCalled();
+            expect(Plugin.prototype._setPlaceholder).not.toHaveBeenCalled();
+            expect(Plugin.prototype._setGeneric).not.toHaveBeenCalled();
+        });
+
         it('checks if pasting into this plugin is allowed', function () {
             spyOn(CMS.Plugin.prototype, '_checkIfPasteAllowed');
+            Plugin.aliasPluginDuplicatesMap = {};
 
             plugin1 = new CMS.Plugin('cms-plugin-1', {
                 type: 'plugin',