[processing] Fix "Random points along line" alg

Avoid various errors in case of empty input layer, empty/null geometries, invalid geometries, linestrings with zero-length segments.
agiudiceandrea · Mar 4, 2024 · 44ce1b2 · 44ce1b2
1 parent b17714c
commit 44ce1b2
Showing 1 changed file with 13 additions and 2 deletions.
diff --git a/python/plugins/processing/algs/qgis/RandomPointsAlongLines.py b/python/plugins/processing/algs/qgis/RandomPointsAlongLines.py
@@ -116,14 +116,22 @@ def processAlgorithm(self, parameters, context, feedback):
 
         ids = source.allFeatureIds()
 
-        while nIterations < maxIterations and nPoints < pointCount:
+        while ids and nIterations < maxIterations and nPoints < pointCount:
             if feedback.isCanceled():
                 break
 
             # pick random feature
             fid = random.choice(ids)
-            f = next(source.getFeatures(request.setFilterFid(fid).setSubsetOfAttributes([])))
+            try:
+                f = next(source.getFeatures(request.setFilterFid(fid).setSubsetOfAttributes([])))
+            except:
+                ids.remove(fid)
+                continue
+
             fGeom = f.geometry()
+            if fGeom.isEmpty():
+                ids.remove(fid)
+                continue
 
             if fGeom.isMultipart():
                 lines = fGeom.asMultiPolyline()
@@ -141,6 +149,9 @@ def processAlgorithm(self, parameters, context, feedback):
             startPoint = vertices[vid]
             endPoint = vertices[vid + 1]
             length = da.measureLine(startPoint, endPoint)
+            if length == 0:
+                nIterations += 1
+                continue
             dist = length * random.random()
 
             d = dist / (length - dist)