prevent snapping to non-geometric layers (was leading to multiple log…

…s: Transform error caught inverse transform of ...)

src/core/qgssnapper.cpp

@@ -54,6 +54,9 @@ int QgsSnapper::snapPoint( const QPoint& startPoint, QList<QgsSnappingResult>& s
   QList<QgsSnapper::SnapLayer>::iterator snapLayerIt;
   for ( snapLayerIt = mSnapLayers.begin(); snapLayerIt != mSnapLayers.end(); ++snapLayerIt )
   {
+    if ( !snapLayerIt->mLayer->hasGeometryType() )
+      continue;
+
     //transform point from map coordinates to layer coordinates
     layerCoordPoint = mMapRenderer->mapToLayerCoordinates( snapLayerIt->mLayer, mapCoordPoint );
 

src/gui/qgsmapcanvassnapper.cpp

@@ -186,7 +186,7 @@ int QgsMapCanvasSnapper::snapToBackgroundLayers( const QPoint& p, QList<QgsSnapp
 
       //layer
       QgsVectorLayer *vlayer = qobject_cast<QgsVectorLayer *>( QgsMapLayerRegistry::instance()->mapLayer( *layerIt ) );
-      if ( !vlayer )
+      if ( !vlayer || !vlayer->hasGeometryType() )
         continue;
 
       snapLayer.mLayer = vlayer;