Bug report #12212
Multiparts to singleparts fails with one-vertex lines
| Status: | Closed | ||
|---|---|---|---|
| Priority: | Normal | ||
| Assignee: |  Victor Olaya | ||
| Category: | Processing/QGIS | ||
| Affected QGIS version: | 2.6.0 | Regression?: | No |
| Operating System: | Easy fix?: | No | |
| Pull Request or Patch supplied: | No | Resolution: | fixed/implemented |
| Crashes QGIS or corrupts data: | No | Copied to github as #: | 20401 |
Description
It is possible to construct lines containing just one vertex, by removing all vertices from a line except one.
However, QgsGeometry.fromPolyline() returns "None" if such a geometry is used as an argument.
Therefore, if a multipart geometry contains a feature of which one of the parts is such an (invisible) one-vertex line, the "Multipart to Singleparts" algorithm fails - both the ftools(?)-version and the processing toolbox version.
As far as I can see, fromPolyline() is just redirected to Geom, so perhaps the "Multipart to Singleparts" processing script should work around this issue.
(In a singlepart layer one could just remove all such one-vertex lines by finding all layer features with length 0, but for multipart geometries this of course doesn't work.)
History
#1
Updated by Daan Goedkoop over 9 years ago
Geom does not allow such shapes; the vector -> check geometry validity tool does indeed report such single-vertex "lines" as an error. So I guess that it is not a bug at all, that the "Multipart to Singleparts" function/script fails in this case.
However, in node-editing mode, still "Check finished (0 errors found)" is displayed in the lower-right corner. Maybe that is not correct, then?
(My QGis interface is in German, I hope the translations back to English make sense)
#2
Updated by Alexander Bruy over 8 years ago
- Resolution set to fixed/implemented
- Status changed from Open to Closed
Works in master. Please reopen if necessary