Accept parent-relation from RELATED-TO property without RELTYPE parameter (#4158)

plugins/libcalendaring/libvcalendar.php

@@ -453,7 +453,8 @@ class libvcalendar implements Iterator
                 break;
 
             case 'RELATED-TO':
-                if ($prop->offsetGet('RELTYPE') == 'PARENT') {
+                $reltype = $prop->offsetGet('RELTYPE');
+                if ($reltype == 'PARENT' || $reltype === null) {
                     $event['parent_id'] = $prop->value;
                 }
                 break;

plugins/libcalendaring/tests/libvcalendar.php

@@ -318,6 +318,7 @@ class libvcalendar_test extends PHPUnit_Framework_TestCase
         $this->assertEquals('IN-PROCESS',   $task['status'],  "Task status property");
         $this->assertEquals(1, count($task['x-custom']),      "Custom properties");
         $this->assertEquals(4, count($task['categories']));
+        $this->assertEquals('1234567890-12345678-PARENT', $task['parent_id'], "Parent Relation");
     }
 
     /**

plugins/libcalendaring/tests/resources/vtodo.ics

@@ -31,6 +31,8 @@ SEQUENCE:2
 CATEGORIES:Tag1,Tag2
 CATEGORIES:Tag3
 CATEGORIES:Tag4
+RELATED-TO:1234567890-12345678-PARENT
+RELATED-TO;RELTYPE=CHILD:1234567890-12345678-CHILD
 X-MOZ-GENERATION:1
 BEGIN:VALARM
 ACTION:DISPLAY