[Qgis-developer] [Processing] Why 2.5D geometries are not clippable ?

[René-Luc Dhont]

Hi Devs,

An issue has been opened by a french user about the clip tool in processing.
http://hub.qgis.org/issues/14929

Because it's not a developper, he does not easily understand why QGIS 
Processing 2.14 does not clip his 2.5D geometry. He does not have this 
issue with QGIS Processing 2.12.

So We test to clip 2.5D geometry with QGIS Processing 2.14 by commenting 
these lines:
```
         geomType = layerA.dataProvider().geometryType()
         if geomType in GEOM_25D:
             raise GeoAlgorithmExecutionException(
                 self.tr('Input layer has unsupported geometry type 
{}').format(geomType))
```
And it seems to work.

So why 2.5D geometries are not clippable in QGIS ?

Regards,
René-Luc