Fix #8864 (Random selection with subsampling broken)

Author: wonder-sk

python/plugins/fTools/tools/doSubsetSelect.py

@@ -92,10 +92,9 @@ def compute(self, inVect, inField, value, perc, progressBar):
         nElement = 0
         self.progressBar.setValue(0)
         self.progressBar.setRange(0, nFeat)
-        fit = vprovider.getFeatures()
         if not len(unique) == mlayer.featureCount():
             for i in unique:
-                fit.rewind()
+                fit = vprovider.getFeatures()
                 FIDs= []
                 while fit.nextFeature(inFeat):
                     atMap = inFeat.attributes()

python/plugins/processing/algs/ftools/RandomSelectionWithinSubsets.py

@@ -99,10 +99,9 @@ def processAlgorithm(self, progress):
         current = 0
         total = 100.0 / float(featureCount * len(unique))
 
-        features = vector.features(layer)
-
         if not len(unique) == featureCount:
             for i in unique:
+                features = vector.features(layer)
                 FIDs = []
                 for inFeat in features:
                     attrs = inFeat.attributes()