QGIS » QGIS Application

1. wkbType() reports wrong layer geometry type
2. densify geometries don't work with multi-geometries

I'll try to fix second ASAP

I don't think that the problem is the MultiGeometries:

$ ogrinfo /home/sam/Scaricati/caminhos_shp/caminhos.shp
INFO: Open of `/home/sam/Scaricati/caminhos_shp/caminhos.shp'
      using driver `ESRI Shapefile' successful.
1: caminhos (Line String)

indeed it is not a MultiLinestring!

Alexander Bruy wrote:

This is because attached layer contains MultiLineString geometry. It is odd that wkbType() for this layer returns 2 (WKBLineString) instead of 5 (WKBMultiLineString). So IMHO here we have two problems:

1. wkbType() reports wrong layer geometry type
2. densify geometries don't work with multi-geometries

I'll try to fix second ASAP

Hi Alex,
this line shape was obtain in QGIS by digitizing a few features and doing a couple of "merge selected features" operations, so really nothing uncommon.

Salvatore Larosa wrote:

I don't think that the problem is the MultiGeometries:

[...]

indeed it is not a MultiLinestring!

Well, take a look at geometry with FID = 1. This one is MultiGeometry and you can easy check this in Python console

>>> layer = qgis.utils.iface.mapCanvas().currentLayer()
>>> ft = QgsFeature()
>>> layer.featureAtId(1, ft)
True
>>> ft.geometry().wkbType()
5

Giovanni Manghi wrote:

this line shape was obtain in QGIS by digitizing a few features and doing a couple of "merge selected features" operations, so really nothing uncommon.

Ah, so root of the problem is that "merge selected features" sometimes creates MultiGeometries (e.g. when there is a small distance between two features. Maybe when snapping is not used during digitizing, or something like this)

Anyway I add MultiLineString support in 033d58d454, and now attached file processed correctly. Now working on MultiPolygon support

Well,

FID 0,2,3 wkbType() returns 2 and isMultipart() returns False;
FID 1 wkbType() returns 5 and isMultipart() returns True.

Is it conceptually correct?

Now I begin to understand the issues #5547, #5328!
Could help Jürgen's fix(#5109)?

Alexander Bruy wrote:

As I understand, shapefile can contain in LineString layer also MultiLineString geometries, and in MultiLineString layer simple LineString geometries (same for points and polygons). "Merge selected features" tool sometimes (when input features have some distance between them) produces multi-geometry. Modifying shapefile didn't change it type, so it continues to report old LineString type.

Multipolygon support added in 2607535b3f, so I close this ticket. Please reopen if necessary

Hi Alex, thanks for this! I will give it a try asap!

The "ftools" category is being removed from the tracker, changing the category of this ticket to "Processing/QGIS" to not leave the category orphaned.