New parent attrib in ubz

src/adaptors/UBSvgSubsetAdaptor.cpp

@@ -1664,6 +1664,9 @@ void UBSvgSubsetAdaptor::UBSvgSubsetWriter::polygonItemToSvgPolygon(UBGraphicsPo
         }
 
         mXmlWriter.writeAttribute(UBSettings::uniboardDocumentNamespaceUri, "uuid", UBStringUtils::toCanonicalUuid(polygonItem->uuid()));
+        if (polygonItem->parentItem()) {
+            mXmlWriter.writeAttribute(UBSettings::uniboardDocumentNamespaceUri, "parent", UBStringUtils::toCanonicalUuid(UBGraphicsItem::getOwnUuid(polygonItem->parentItem())));
+        }
 
         mXmlWriter.writeEndElement();
     }