3 files changed, 3 insertions, 3 deletions
diff --git a/3rdparty/Sabre/DAV/Property/Href.php b/3rdparty/Sabre/DAV/Property/Href.php
index dac564f24d7..cd1d867f71b 100755
--- a/3rdparty/Sabre/DAV/Property/Href.php
+++ b/3rdparty/Sabre/DAV/Property/Href.php
@@ -82,7 +82,7 @@ class Sabre_DAV_Property_Href extends Sabre_DAV_Property implements Sabre_DAV_Pr
      */
     static function unserialize(DOMElement $dom) {
 
-        if (Sabre_DAV_XMLUtil::toClarkNotation($dom->firstChild)==='{DAV:}href') {
+        if ($dom->firstChild && Sabre_DAV_XMLUtil::toClarkNotation($dom->firstChild)==='{DAV:}href') {
             return new self($dom->firstChild->textContent,false);
         }
 
diff --git a/3rdparty/Sabre/DAV/Property/HrefList.php b/3rdparty/Sabre/DAV/Property/HrefList.php
index 7a52272e885..282c452ca0b 100755
--- a/3rdparty/Sabre/DAV/Property/HrefList.php
+++ b/3rdparty/Sabre/DAV/Property/HrefList.php
@@ -79,7 +79,7 @@ class Sabre_DAV_Property_HrefList extends Sabre_DAV_Property {
      * It will only decode {DAV:}href values.
      *
      * @param DOMElement $dom
-     * @return Sabre_DAV_Property_Href
+     * @return Sabre_DAV_Property_HrefList
      */
     static function unserialize(DOMElement $dom) {
 
diff --git a/3rdparty/Sabre/DAV/Property/Response.php b/3rdparty/Sabre/DAV/Property/Response.php
index 88afbcfb26d..9f21163d12e 100755
--- a/3rdparty/Sabre/DAV/Property/Response.php
+++ b/3rdparty/Sabre/DAV/Property/Response.php
@@ -138,7 +138,7 @@ class Sabre_DAV_Property_Response extends Sabre_DAV_Property implements Sabre_DA
                 if (is_scalar($propertyValue)) {
                     $text = $document->createTextNode($propertyValue);
                     $currentProperty->appendChild($text);
-                } elseif ($propertyValue instanceof Sabre_DAV_Property) {
+                } elseif ($propertyValue instanceof Sabre_DAV_PropertyInterface) {
                     $propertyValue->serialize($server,$currentProperty);
                 } elseif (!is_null($propertyValue)) {
                     throw new Sabre_DAV_Exception('Unknown property value type: ' . gettype($propertyValue) . ' for property: ' . $propertyName);