Index: branches/5.3.x/core/units/categories/categories_event_handler.php
===================================================================
diff -u -N -r16519 -r16600
--- branches/5.3.x/core/units/categories/categories_event_handler.php	(.../categories_event_handler.php)	(revision 16519)
+++ branches/5.3.x/core/units/categories/categories_event_handler.php	(.../categories_event_handler.php)	(revision 16600)
@@ -1,6 +1,6 @@
 <?php
 /**
-* @version	$Id: categories_event_handler.php 16519 2017-01-20 20:21:46Z alex $
+* @version	$Id: categories_event_handler.php 16600 2017-07-29 06:19:27Z alex $
 * @package	In-Portal
 * @copyright	Copyright (C) 1997 - 2009 Intechnic. All rights reserved.
 * @license      GNU/GPL
@@ -149,8 +149,8 @@
 		 */
 		function _getMassPermissionEvents()
 		{
-			return Array (
-				'OnEdit', 'OnSave', 'OnMassDelete', 'OnMassApprove',
+			return array(
+				'OnStoreSelected', 'OnEdit', 'OnSave', 'OnMassDelete', 'OnMassApprove',
 				'OnMassDecline', 'OnMassMoveUp', 'OnMassMoveDown',
 				'OnCut',
 			);
@@ -222,6 +222,40 @@
 		}
 
 		/**
+		 * 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
@@ -1350,6 +1384,41 @@
 		}
 
 		/**
+		 * Validates category data.
+		 *
+		 * @param kEvent $event Event.
+		 *
+		 * @return void
+		 */
+		protected function OnBeforeItemValidate(kEvent $event)
+		{
+			parent::OnBeforeItemValidate($event);
+
+			/** @var kDBItem $object */
+			$object = $event->getObject();
+
+			$friendly_url = $object->GetDBField('FriendlyURL');
+
+			if ( strlen($friendly_url) && $friendly_url != $object->GetOriginalField('FriendlyURL') ) {
+				$sql = 'SELECT CategoryId
+						FROM %s
+						WHERE NamedParentPath = ' . $this->Conn->qstr('Content/' . $friendly_url);
+				$duplicate_id = $this->Conn->GetOne(sprintf($sql, $object->TableName));
+
+				if ( $duplicate_id === false && $object->IsTempTable() ) {
+					$duplicate_id = $this->Conn->GetOne(sprintf(
+						$sql,
+						$this->Application->GetLiveName($object->TableName)
+					));
+				}
+
+				if ( $duplicate_id !== false ) {
+					$object->SetError('FriendlyURL', 'unique');
+				}
+			}
+		}
+
+		/**
 		 * Sets correct status for new categories created on front-end
 		 *
 		 * @param kEvent $event
@@ -1863,8 +1932,20 @@
 			$object->setRequired('PageCacheKey', $object->GetDBField('OverridePageCacheKey'));
 			$object->SetDBField('Template', $this->_stripTemplateExtension( $object->GetDBField('Template') ));
 
-			if ($object->GetDBField('Type') == PAGE_TYPE_TEMPLATE) {
-				if (!$this->_templateFound($object->GetDBField('Template'), $object->GetDBField('ThemeId'))) {
+			$category_type = $object->GetDBField('Type');
+
+			// Changing category type would associate/disassociate it to theme.
+			if ( $category_type != $object->GetOriginalField('Type') ) {
+				if ( $category_type == PAGE_TYPE_TEMPLATE ) {
+					$object->SetDBField('ThemeId', $this->_getCurrentThemeId());
+				}
+				else {
+					$object->SetDBField('ThemeId', 0);
+				}
+			}
+
+			if ( $category_type == PAGE_TYPE_TEMPLATE ) {
+				if ( !$this->_templateFound($object->GetDBField('Template'), $object->GetDBField('ThemeId')) ) {
 					$object->SetError('Template', 'template_file_missing', 'la_error_TemplateFileMissing');
 				}
 			}