ZP-441 #comment Email flagged on an iPhone is without subject in task view #time 1h

git-svn-id: https://z-push.org/svn/z-push/trunk@1713 b7dd7b3b-3a3c-0410-9da9-bee62a6cc5b5

src/backend/zarafa/mapiprovider.php

@@ -1014,7 +1014,8 @@ class MAPIProvider {
         else {
             $this->setPropsInMAPI($mapimessage, $message->flag, $flagmapping);
             $props[$flagprops["todoitemsflags"]] = 1;
-            $props[$flagprops["todotitle"]] = $message->subject;
+            if (isset($message->subject) && str_len($message->subject) > 0)
+                $props[$flagprops["todotitle"]] = $message->subject;
             // ordinal date is utc current time
             if (!isset($message->flag->ordinaldate) || empty($message->flag->ordinaldate)) {
                 $props[$flagprops["ordinaldate"]] = time();