Fix for bug #1570, move vertex after add vertex introduces new vertices when snapping is active

git-svn-id: http://svn.osgeo.org/qgis/trunk@10517 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: mhugent

src/app/qgsmaptooladdvertex.cpp

@@ -96,7 +96,25 @@ void QgsMapToolAddVertex::canvasReleaseEvent( QMouseEvent * e )
       int topologicalEditing = QgsProject::instance()->readNumEntry( "Digitizing", "/TopologicalEditing", 0 );
       if ( topologicalEditing )
       {
-        insertSegmentVerticesForSnap( snapResults, vlayer );
+        //ignore the snapping results that are on features / segments already considered in mRecentSnappingResults
+        QList<QgsSnappingResult> filteredSnapResults = snapResults;
+        QList<QgsSnappingResult>::iterator recentIt = mRecentSnappingResults.begin();
+        for(; recentIt != mRecentSnappingResults.end(); ++recentIt)
+        {
+            QList<QgsSnappingResult>::iterator filterIt = filteredSnapResults.begin();
+            for(; filterIt != filteredSnapResults.end(); ++filterIt)
+            {
+                if(filterIt->snappedAtGeometry == recentIt->snappedAtGeometry \
+                    && filterIt->snappedVertexNr == recentIt->snappedVertexNr \
+                    && filterIt->beforeVertexNr == recentIt->beforeVertexNr )
+                {
+                    filteredSnapResults.erase(filterIt);
+                    continue;
+                }
+
+            }
+        }
+        insertSegmentVerticesForSnap( filteredSnapResults, vlayer );
       }
 
       snappedPointMapCoord = snapPointFromResults( snapResults, e->pos() );