Fix memory leaks in QgsMapCanvasSnapper

Author: nyalldawson

src/gui/qgsmapcanvassnapper.cpp

@@ -305,10 +305,12 @@ int QgsMapCanvasSnapper::snapToBackgroundLayers( const QgsPoint& point, QList<Qg
       QVector<QgsPoint> vertexPoints;
       vertexPoints.append( iSegIt->beforeVertex );
       vertexPoints.append( iSegIt->afterVertex );
-      QgsGeometry* lineB = QgsGeometry::fromPolyline( vertexPoints );
 
+      QgsGeometry* lineB = QgsGeometry::fromPolyline( vertexPoints );
       QgsGeometry* intersectionPoint = lineA->intersection( lineB );
-      if ( intersectionPoint->type()  == QGis::Point )
+      delete lineB;
+
+      if ( intersectionPoint && intersectionPoint->type() == QGis::Point )
       {
         //We have to check the intersection point is inside the tolerance distance for both layers
         double toleranceA = 0;
@@ -331,8 +333,13 @@ int QgsMapCanvasSnapper::snapToBackgroundLayers( const QgsPoint& point, QList<Qg
           iSegIt->snappedVertex = intersectionPoint->asPoint();
           myResults.append( *iSegIt );
         }
+        delete cursorPoint;
       }
+      delete intersectionPoint;
+
     }
+
+    delete lineA;
   }
 
   if ( myResults.length() > 0 )