Index: branches/5.2.x/core/kernel/managers/cache_manager.php
===================================================================
diff -u -N -r16513 -r16664
--- branches/5.2.x/core/kernel/managers/cache_manager.php	(.../cache_manager.php)	(revision 16513)
+++ branches/5.2.x/core/kernel/managers/cache_manager.php	(.../cache_manager.php)	(revision 16664)
@@ -1,6 +1,6 @@
 <?php
 /**
-* @version	$Id: cache_manager.php 16513 2017-01-20 14:10:53Z alex $
+* @version	$Id: cache_manager.php 16664 2021-01-11 08:51:24Z alex $
 * @package	In-Portal
 * @copyright	Copyright (C) 1997 - 2011 Intechnic. All rights reserved.
 * @license      GNU/GPL
@@ -800,12 +800,29 @@
 			$this->setCache($serial_name, (int)$this->getCache($serial_name) + 1);
 
 			if (!defined('IS_INSTALL') || !IS_INSTALL) {
-				// delete cached mod-rewrite urls related to given prefix and id
-				$delete_clause = isset($id) ? $prefix . ':' . $id : $prefix;
+				if ( $this->Application->isCachingType(CACHING_TYPE_MEMORY) ) {
+					$prefixes = $this->Application->getCache('cached_urls_unit_prefixes');
+				}
+				else {
+					$prefixes = $this->Application->getDBCache('cached_urls_unit_prefixes');
 
-				$sql = 'DELETE FROM ' . TABLE_PREFIX . 'CachedUrls
-						WHERE Prefixes LIKE ' . $this->Conn->qstr('%|' . $delete_clause . '|%');
-				$this->Conn->Query($sql);
+					if ( $prefixes !== false ) {
+						$prefixes = unserialize($prefixes);
+					}
+				}
+
+				if ( !$prefixes ) {
+					$prefixes = array('c', 'lang', 'theme');
+				}
+
+				if ( in_array($prefix, $prefixes) ) {
+					// delete cached mod-rewrite urls related to given prefix and id
+					$delete_clause = isset($id) ? $prefix . ':' . $id : $prefix;
+
+					$sql = 'DELETE FROM ' . TABLE_PREFIX . 'CachedUrls
+							WHERE Prefixes LIKE ' . $this->Conn->qstr('%|' . $delete_clause . '|%');
+					$this->Conn->Query($sql);
+				}
 			}
 		}