From 56cddd1e2cf1ef2c1b6a11dd57063c9907cc5ae5 Mon Sep 17 00:00:00 2001
From: Thomas Bruederli <bruederli@kolabsys.com>
Date: Wed, 21 Nov 2012 22:17:20 +0100
Subject: [PATCH] Fix iCal export: no empty organizer or attendee attributes;
 correctly escape special characters

---
 plugins/calendar/lib/calendar_ical.php | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/plugins/calendar/lib/calendar_ical.php b/plugins/calendar/lib/calendar_ical.php
index 601ac864..f77224dc 100644
--- a/plugins/calendar/lib/calendar_ical.php
+++ b/plugins/calendar/lib/calendar_ical.php
@@ -454,9 +454,12 @@ class calendar_ical
     }
   }
 
+  /**
+   * Escape values according to RFC 2426 2.5
+   */
   private function escpape($str)
   {
-    return preg_replace('/(?<!\\\\)([\:\;\,\\n\\r])/', '\\\$1', $str);
+    return strtr($str, array('\\' => '\\\\', ';' => '\\;', ',' => '\\,'));
   }
 
   /**
@@ -469,14 +472,15 @@ class calendar_ical
     $organizer = "";
     $attendees = "";
     foreach ($ats as $at) {
-      if ($at['role']=="ORGANIZER") {
-        //I am an orginizer
-        $organizer .= "ORGANIZER;";
-        if (!empty($at['name']))
-          $organizer .= 'CN="' . $at['name'] . '"';
-        $organizer .= ":mailto:". $at['email'] . self::EOL;
+      if ($at['role'] == "ORGANIZER") {
+        if ($at['email']) {
+          $organizer .= "ORGANIZER;";
+          if (!empty($at['name']))
+            $organizer .= 'CN="' . $at['name'] . '"';
+          $organizer .= ":mailto:". $at['email'] . self::EOL;
+        }
       }
-      else {
+      else if ($at['email']) {
         //I am an attendee 
         $attendees .= "ATTENDEE;ROLE=" . $at['role'] . ";PARTSTAT=" . $at['status'];
         if ($at['rsvp'])