WFS server error. Invalid or Unsupported FILTER in GetFeature

[landam]

Steps to reproduce:

wfs = WebFeatureService(url='http://geo102.fsv.cvut.cz/services/ghwfs', version='1.1.0')
filter_ = PropertyIsEqualTo(propertyname='nuts0', literal='CZ')
filterxml = etree.tostring(filter_.toXML()).decode("utf-8")
response = wfs.getfeature(typename='lucas', filter=filterxml)

returns:

<?xml version="1.0" encoding="UTF-8"?>
<ows:ExceptionReport xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:ows="http://www.opengis.net/ows" version="1.1.0" language="en-US" xsi:schemaLocation="http://www.opengis.net/ows http://schemas.opengis.net/ows/1.0.0/owsExceptionReport.xsd">
  <ows:Exception exceptionCode="InvalidParameterValue" locator="filter">
    <ows:ExceptionText>msWFSGetFeature(): WFS server error. Invalid or Unsupported FILTER in GetFeature : &lt;ogc:PropertyIsEqualTo xmlns:ogc="http://www.opengis.net/ogc"&gt;&lt;ogc:PropertyName&gt;nuts0&lt;/ogc:PropertyName&gt;&lt;ogc:Literal&gt;CZ&lt;/ogc:Literal&gt;&lt;/ogc:PropertyIsEqualTo&gt;</ows:ExceptionText>
  </ows:Exception>
</ows:ExceptionReport>

Mapserver used:

mapserv -v
MapServer version 7.2.2 OUTPUT=PNG OUTPUT=JPEG OUTPUT=KML SUPPORTS=PROJ SUPPORTS=AGG SUPPORTS=FREETYPE SUPPORTS=CAIRO SUPPORTS=SVG_SYMBOLS SUPPORTS=RSVG SUPPORTS=ICONV SUPPORTS=FRIBIDI SUPPORTS=WMS_SERVER SUPPORTS=WMS_CLIENT SUPPORTS=WFS_SERVER SUPPORTS=WFS_CLIENT SUPPORTS=WCS_SERVER SUPPORTS=SOS_SERVER SUPPORTS=FASTCGI SUPPORTS=THREADS SUPPORTS=GEOS SUPPORTS=PBF INPUT=JPEG INPUT=POSTGIS INPUT=OGR INPUT=GDAL INPUT=SHAPEFILE

It seems that ogc:PropertyIsEqualTo is supported by the Mapserver (see Capabilities):

<ogc:ComparisonOperator>EqualTo</ogc:ComparisonOperator>

Additional question:

• Why ServiceException is not raised in this case?