Fix performance issue in message_headers_output hook handling,

Update version number

plugins/managesieve/Changelog

@@ -1,7 +1,8 @@
-* version 5.2 [2012-07-23]
+* version 5.2 [2012-07-24]
 -----------------------------------------------------------
 - Added GUI for variables setting - RFC5229 (patch from Paweł Słowik)
 - Fixed scrollbars in Larry's iframes
+- Fix performance issue in message_headers_output hook handling
 
 * version 5.1 [2012-06-21]
 -----------------------------------------------------------

plugins/managesieve/managesieve.php

@@ -64,7 +64,7 @@ class managesieve extends rcube_plugin
         "x-beenthere",
     );
 
-    const VERSION = '5.0';
+    const VERSION = '5.2';
     const PROGNAME = 'Roundcube (Managesieve)';
 
 
@@ -145,6 +145,13 @@ class managesieve extends rcube_plugin
      */
     function mail_headers($args)
     {
+        // this hook can be executed many times
+        if ($this->mail_headers_done) {
+            return $args;
+        }
+
+        $this->mail_headers_done = true;
+
         $headers = $args['headers'];
         $ret     = array();