[BUGFIX][QGIS Server] WFS DescribeFeatureType Geometry element type

In the OGR provider, we can read:
```
Some ogr drivers (e.g. GML) are not able to determine the geometry type of a layer like this.
In such cases, we use virtual sublayers for each geometry if the layer contains
multiple geometries (see subLayers) otherwise we guess geometry type from first feature
```
It means that in DescribeFeatureType Geometry element can be describe as simple and the GML contains
simple and multi. It's not XML valid.
To fix it, for OGR provider Geometry element type is set to `gml:GeometryPropertyType`

For the next release, it will be interesting to allow users to specify whether the geometries are multi.

src/server/qgswfsprojectparser.cpp

@@ -400,40 +400,50 @@ void QgsWFSProjectParser::describeFeatureType( const QString& aTypeName, QDomEle
         extensionElem.appendChild( sequenceElem );
 
         //xsd:element
-        QDomElement geomElem = doc.createElement( "element"/*xsd:element*/ );
-        geomElem.setAttribute( "name", "geometry" );
-        QGis::WkbType wkbType = layer->wkbType();
-        if ( wkbType != QGis::WKBNoGeometry )
+        if ( layer->hasGeometryType() )
         {
-          switch ( wkbType )
+          QDomElement geomElem = doc.createElement( "element"/*xsd:element*/ );
+          geomElem.setAttribute( "name", "geometry" );
+          if ( provider->name() == "ogr" )
+          {
+            // because some ogr drivers (e.g. ESRI ShapeFile, GML)
+            // are not able to determine the geometry type of a layer.
+            // we set to GeometryType
+            geomElem.setAttribute( "type", "gml:GeometryPropertyType" );
+          }
+          else
           {
-            case QGis::WKBPoint25D:
-            case QGis::WKBPoint:
-              geomElem.setAttribute( "type", "gml:PointPropertyType" );
-              break;
-            case QGis::WKBLineString25D:
-            case QGis::WKBLineString:
-              geomElem.setAttribute( "type", "gml:LineStringPropertyType" );
-              break;
-            case QGis::WKBPolygon25D:
-            case QGis::WKBPolygon:
-              geomElem.setAttribute( "type", "gml:PolygonPropertyType" );
-              break;
-            case QGis::WKBMultiPoint25D:
-            case QGis::WKBMultiPoint:
-              geomElem.setAttribute( "type", "gml:MultiPointPropertyType" );
-              break;
-            case QGis::WKBMultiLineString25D:
-            case QGis::WKBMultiLineString:
-              geomElem.setAttribute( "type", "gml:MultiLineStringPropertyType" );
-              break;
-            case QGis::WKBMultiPolygon25D:
-            case QGis::WKBMultiPolygon:
-              geomElem.setAttribute( "type", "gml:MultiPolygonPropertyType" );
-              break;
-            default:
-              geomElem.setAttribute( "type", "gml:GeometryPropertyType" );
-              break;
+            QGis::WkbType wkbType = layer->wkbType();
+            switch ( wkbType )
+            {
+              case QGis::WKBPoint25D:
+              case QGis::WKBPoint:
+                geomElem.setAttribute( "type", "gml:PointPropertyType" );
+                break;
+              case QGis::WKBLineString25D:
+              case QGis::WKBLineString:
+                geomElem.setAttribute( "type", "gml:LineStringPropertyType" );
+                break;
+              case QGis::WKBPolygon25D:
+              case QGis::WKBPolygon:
+                geomElem.setAttribute( "type", "gml:PolygonPropertyType" );
+                break;
+              case QGis::WKBMultiPoint25D:
+              case QGis::WKBMultiPoint:
+                geomElem.setAttribute( "type", "gml:MultiPointPropertyType" );
+                break;
+              case QGis::WKBMultiLineString25D:
+              case QGis::WKBMultiLineString:
+                geomElem.setAttribute( "type", "gml:MultiLineStringPropertyType" );
+                break;
+              case QGis::WKBMultiPolygon25D:
+              case QGis::WKBMultiPolygon:
+                geomElem.setAttribute( "type", "gml:MultiPolygonPropertyType" );
+                break;
+              default:
+                geomElem.setAttribute( "type", "gml:GeometryPropertyType" );
+                break;
+            }
           }
           geomElem.setAttribute( "minOccurs", "0" );
           geomElem.setAttribute( "maxOccurs", "1" );
@@ -453,30 +463,30 @@ void QgsWFSProjectParser::describeFeatureType( const QString& aTypeName, QDomEle
           }
 
           //xsd:element
-          QDomElement geomElem = doc.createElement( "element"/*xsd:element*/ );
-          geomElem.setAttribute( "name", attributeName );
+          QDomElement attElem = doc.createElement( "element"/*xsd:element*/ );
+          attElem.setAttribute( "name", attributeName );
           QVariant::Type attributeType = fields[idx].type();
           if ( attributeType == QVariant::Int )
-            geomElem.setAttribute( "type", "integer" );
+            attElem.setAttribute( "type", "integer" );
           else if ( attributeType == QVariant::Double )
-            geomElem.setAttribute( "type", "double" );
+            attElem.setAttribute( "type", "double" );
           else if ( attributeType == QVariant::Bool )
-            geomElem.setAttribute( "type", "boolean" );
+            attElem.setAttribute( "type", "boolean" );
           else if ( attributeType == QVariant::Date )
-            geomElem.setAttribute( "type", "date" );
+            attElem.setAttribute( "type", "date" );
           else if ( attributeType == QVariant::Time )
-            geomElem.setAttribute( "type", "time" );
+            attElem.setAttribute( "type", "time" );
           else if ( attributeType == QVariant::DateTime )
-            geomElem.setAttribute( "type", "dateTime" );
+            attElem.setAttribute( "type", "dateTime" );
           else
-            geomElem.setAttribute( "type", "string" );
+            attElem.setAttribute( "type", "string" );
 
-          sequenceElem.appendChild( geomElem );
+          sequenceElem.appendChild( attElem );
 
           QString alias = layer->attributeAlias( idx );
           if ( !alias.isEmpty() )
           {
-            geomElem.setAttribute( "alias", alias );
+            attElem.setAttribute( "alias", alias );
           }
         }
       }

tests/testdata/qgis_server/wfs_describefeaturetype.txt

@@ -8,7 +8,7 @@ Content-Type: text/xml; charset=utf-8
   <complexContent>
    <extension base="gml:AbstractFeatureType">
     <sequence>
-     <element minOccurs="0" maxOccurs="1" type="gml:PointPropertyType" name="geometry"/>
+     <element minOccurs="0" maxOccurs="1" type="gml:GeometryPropertyType" name="geometry"/>
      <element type="integer" name="id"/>
      <element type="string" name="name"/>
      <element type="string" name="utf8nameè"/>