Namespaces are not considered when parsing kml

[Stadly]

It seems that namespaces are not taken into account when parsing kml files.

This file, with http://www.opengis.net/kml/2.2 as the default namespace, can correctly be converted to gpx format:

<kml xmlns="http://www.opengis.net/kml/2.2">
   <Document>
      <Placemark>
         <TimeSpan>
            <begin>2019-11-28T09:10:47.973Z</begin>
            <end>2019-11-28T09:18:30.731Z</end>
         </TimeSpan>
         <LineString>
            <coordinates>5.6503587,58.726241099999996,0 5.69573010002664,58.72640951793773,0</coordinates>
         </LineString>
      </Placemark>
   </Document>
</kml>

This file, which should be entirely equivalent, other than the namespace being called ns instead of being the default namespace, cannot be converted to gpx format:

<ns:kml xmlns:ns="http://www.opengis.net/kml/2.2">
   <ns:Document>
      <ns:Placemark>
         <ns:TimeSpan>
            <ns:begin>2019-11-28T09:10:47.973Z</ns:begin>
            <ns:end>2019-11-28T09:18:30.731Z</ns:end>
         </ns:TimeSpan>
         <ns:LineString>
            <ns:coordinates>5.6503587,58.726241099999996,0 5.69573010002664,58.72640951793773,0</ns:coordinates>
         </ns:LineString>
      </ns:Placemark>
   </ns:Document>
</ns:kml>

GPSBabel reports "Translation successful", but the converted file looks like this:

<gpx version="1.0" creator="GPSBabel - http://www.gpsbabel.org" xmlns="http://www.topografix.com/GPX/1/0">
  <time>2020-02-17T12:34:46.930Z</time>
</gpx>

This file, which is not valid kml, since it does not use namespaces, can correctly be converted to gpx format:

<kml>
   <Document>
      <Placemark>
         <TimeSpan>
            <begin>2019-11-28T09:10:47.973Z</begin>
            <end>2019-11-28T09:18:30.731Z</end>
         </TimeSpan>
         <LineString>
            <coordinates>5.6503587,58.726241099999996,0 5.69573010002664,58.72640951793773,0</coordinates>
         </LineString>
      </Placemark>
   </Document>
</kml>