2 files changed, 22 insertions, 4 deletions
diff --git a/phpBB/includes/acm/acm_memory.php b/phpBB/includes/acm/acm_memory.php
index fd9b9ff342..1ed4fb0d55 100644
--- a/phpBB/includes/acm/acm_memory.php
+++ b/phpBB/includes/acm/acm_memory.php
@@ -39,7 +39,7 @@ class acm_memory
 		global $phpbb_root_path, $dbname, $table_prefix;
 
 		$this->cache_dir	= $phpbb_root_path . 'cache/';
-		$this->key_prefix	= md5($dbname, $table_prefix) . '_';
+		$this->key_prefix	= substr(md5($dbname . $table_prefix), 0, 8) . '_';
 
 		if (!isset($this->extension) || !extension_loaded($this->extension))
 		{
diff --git a/phpBB/includes/acm/acm_xcache.php b/phpBB/includes/acm/acm_xcache.php
index ad527b8220..d0a614660c 100644
--- a/phpBB/includes/acm/acm_xcache.php
+++ b/phpBB/includes/acm/acm_xcache.php
@@ -25,10 +25,25 @@ if (!class_exists('acm_memory'))
 /**
 * ACM for XCache
 * @package acm
+*
+* To use this module you need ini_get() enabled and the following INI settings configured as follows:
+* - xcache.var_size > 0
+* - xcache.admin.enable_auth = off (or xcache.admin.user and xcache.admin.password set)
+*
 */
 class acm extends acm_memory
 {
-	var $extension = 'xcache';
+	var $extension = 'XCache';
+
+	function acm()
+	{
+		parent::acm_memory();
+
+		if (!function_exists('ini_get') || (int) ini_get('xcache.var_size') <= 0)
+		{
+			trigger_error('Increase xcache.var_size setting above 0 or enable ini_get() to use this ACM module.', E_USER_ERROR);
+		}
+	}
 
 	/**
 	* Purge cache data
@@ -37,14 +52,17 @@ class acm extends acm_memory
 	*/
 	function purge()
 	{
+		// Run before for XCache, if admin functions are disabled it will terminate execution
+		parent::purge();
+
+		// If the admin authentication is enabled but not set up, this will cause a nasty error.
+		// Not much we can do about it though.
 		$n = xcache_count(XC_TYPE_VAR);
 
 		for ($i = 0; $i < $n; $i++)
 		{
 			xcache_clear_cache(XC_TYPE_VAR, $i);
 		}
-
-		parent::purge();
 	}
 
 	/**