CRM-12059: Replaced bad conditional (always true) with an accurate, m…

…ore readable, and more efficient one.

Added some code documentation and replaced comments about specific Joomla methods with references to external resources.

CRM/Core/Permission/Joomla.php

@@ -140,43 +140,45 @@ public function checkGroupRole($array) {
    */
   public function upgradePermissions($permissions) {
     $translatedPerms = array();
+
+    // Flipping the $permissions array gives us just the raw names of the
+    // permissions. The descriptions, etc., are irrelevant for the purposes of
+    // this method.
     foreach (array_flip($permissions) as $perm) {
       $translated = $this->translateJoomlaPermission($perm);
       $translatedPerms[] = $translated[0];
     }
 
     $associations = $this->getUserGroupPermsAssociations();
-    $originalAssociations = clone $associations;
+    $cmsPermsHaveGoneStale = FALSE;
     foreach (array_keys(get_object_vars($associations)) as $permName) {
       if (!in_array($permName, $translatedPerms)) {
         unset($associations->$permName);
+        $cmsPermsHaveGoneStale = TRUE;
       }
     }
 
-    if ($originalAssociations !== $associations) {
+    if ($cmsPermsHaveGoneStale) {
       $this->updateGroupPermsAssociations($associations);
     }
   }
 
   /**
    * Fetches the associations between user groups and CiviCRM permissions.
    *
+   * @see https://docs.joomla.org/Selecting_data_using_JDatabase
    * @return object
    *   Properties of the object are Joomla-fied permission names.
    */
   private function getUserGroupPermsAssociations() {
-    // Get a db connection.
     $db = JFactory::getDbo();
-    // Create a new query object.
     $query = $db->getQuery(TRUE);
 
-    // Build query to fetch user-group/permission associations.
     $query
         ->select($db->quoteName('rules'))
         ->from($db->quoteName('#__assets'))
         ->where($db->quoteName('name') . ' = ' . $db->quote('com_civicrm'));
 
-    // Reset the query using our newly populated query object.
     $db->setQuery($query);
 
     // Load the result as a stdClass object, decoding JSON on the way
@@ -186,17 +188,15 @@ private function getUserGroupPermsAssociations() {
   /**
    * Writes user-group/permissions associations back to Joomla.
    *
+   * @see https://docs.joomla.org/Inserting,_Updating_and_Removing_data_using_JDatabase
    * @param object $associations
    *   Same format as the return of
    *   CRM_Core_Permission_Joomla->getUserGroupPermsAssociations().
    */
   private function updateGroupPermsAssociations($associations) {
-    // Get a db connection.
     $db = JFactory::getDbo();
-    // Create a new query object.
     $query = $db->getQuery(TRUE);
 
-    // Build query to update CiviCRM's user-group/permission associations.
     $query
         ->update($db->quoteName('#__assets'))
         ->set($db->quoteName('rules') . ' = ' . $db->quote(json_encode($associations)))