Index: branches/5.2.x/core/units/categories/categories_event_handler.php
===================================================================
diff -u -N -r16560 -r16563
--- branches/5.2.x/core/units/categories/categories_event_handler.php	(.../categories_event_handler.php)	(revision 16560)
+++ branches/5.2.x/core/units/categories/categories_event_handler.php	(.../categories_event_handler.php)	(revision 16563)
@@ -1,6 +1,6 @@
 <?php
 /**
-* @version	$Id: categories_event_handler.php 16560 2017-07-16 13:17:03Z alex $
+* @version	$Id: categories_event_handler.php 16563 2017-07-16 15:12:46Z alex $
 * @package	In-Portal
 * @copyright	Copyright (C) 1997 - 2009 Intechnic. All rights reserved.
 * @license      GNU/GPL
@@ -221,6 +221,40 @@
 		}
 
 		/**
+		 * Creates "EDITING_MODE" constant.
+		 *
+		 * @param kEvent $event Event.
+		 *
+		 * @return void
+		 */
+		protected function OnAfterStartupHook(kEvent $event)
+		{
+			if ( !$this->Application->GetVar('admin') ) {
+				// User can't edit anything.
+				kUtil::safeDefine('EDITING_MODE', '');
+
+				return;
+			}
+
+			/** @var Session $admin_session */
+			$admin_session = $this->Application->recallObject('Session.admin');
+
+			// Store Admin Console User's ID to Front-End's session for cross-session permission checks.
+			$this->Application->StoreVar('admin_user_id', (int)$admin_session->RecallVar('user_id'));
+
+			$base_category = $this->Application->getBaseCategory();
+
+			if ( $this->Application->CheckAdminPermission('CATEGORY.MODIFY', 0, $base_category) ) {
+				// User can edit cms blocks (when viewing front-end through admin's frame).
+				$editing_mode = $this->Application->GetVar('editing_mode');
+				define('EDITING_MODE', $editing_mode ? $editing_mode : EDITING_MODE_BROWSE);
+			}
+
+			// User can't edit anything.
+			kUtil::safeDefine('EDITING_MODE', '');
+		}
+
+		/**
 		 * Set's mark, that root category is edited
 		 *
 		 * @param kEvent $event