[ftools] Fix Line Intersection (Fix #8114)

Author: m-kuhn

python/plugins/fTools/tools/doIntersectLines.py

@@ -144,7 +144,7 @@ def compute(self, line1, line2, field1, field2, outPath, progressBar):
 
         index = ftools_utils.createIndex( provider2 )
 
-        fit1 = vprovider.getFeatures( QgsFeatureRequest().setSubsetOfAttributes([index1]) )
+        fit1 = provider1.getFeatures( QgsFeatureRequest().setSubsetOfAttributes([index1]) )
         while fit1.nextFeature(inFeat):
             inGeom = inFeat.geometry()
             v1 = inFeat.attributes()[index1]