Bug report #21603
Crash when using QgsGeometry.delaunayTriangulation()
| Status: | Closed | ||
|---|---|---|---|
| Priority: | High | ||
| Assignee: | - | ||
| Category: | Python bindings / sipify | ||
| Affected QGIS version: | 3.7(master) | Regression?: | No |
| Operating System: | Windows 10 | Easy fix?: | No |
| Pull Request or Patch supplied: | No | Resolution: | invalid |
| Crashes QGIS or corrupts data: | Yes | Copied to github as #: | 29419 |
Description
Qgis crashes (with windows message "qgis-dev-bin-g7.exe has stopped working") after using QgsGeometry.delaunayTriangulation() in python script.
It reproduces when executing the attached processing script with the attached point layer.
Running the following code in python console can also trigger the crash, but it's sometimes necessary to run it twice:
pointLayer = iface.activeLayer()
multiPoint = QgsMultiPoint()
for pointFeature in pointLayer.getFeatures():
multiPoint.addGeometry(pointFeature.geometry().vertexAt(0))
multiPointGeometry = QgsGeometry(multiPoint)
triangulation = multiPointGeometry.delaunayTriangulation(1e-3)
multiTriangle = triangulation.get()
for i in range(multiTriangle.numGeometries()):
triangle = multiTriangle.geometryN(i)
triangleGeometry = QgsGeometry(triangle)
test_points.dbf (110 Bytes)
test_points.cpg (5 Bytes)
test_points.prj (431 Bytes)
test_points.qpj (682 Bytes)
test_points.shp (212 Bytes)
test_points.shx (132 Bytes)
TestTriangulation.py 
(1.88 KB)
History
#1
Updated by Nyall Dawson about 5 years ago
- Resolution set to invalid
- Status changed from Open to Closed
triangleGeometry = QgsGeometry(triangle)
Should be
triangleGeometry = QgsGeometry(triangle.clone())
You are "stealing" ownership of an already owned object, which leads to a crash
#2
Updated by Antoine Lafranchis about 5 years ago
Thanks, it works fine now!
Isn't it possible to throw exceptions instead of crashing in cases of ownership theft?
#3
Updated by Nyall Dawson about 5 years ago
I think it should be, but generating these bindings is very complex and sometimes fragile, so I'm not 100% confident. I'll give it a shot sometime.