PCLVisualizer shape handling is bad

[VictorLamoine]

This simple example will crash the PCLVisualizer:

#include <pcl/io/pcd_io.h>
#include <pcl/visualization/pcl_visualizer.h>

int
main (int argc,
      char *argv[])
{
  pcl::visualization::PCLVisualizer viewer ("Viewer");
  viewer.addText("coucou", 50, 50, "text");
  pcl::PointXYZ p1 (0, 0, 0), p2 (1, 1, 1);
  viewer.addLine(p1, p2, "line");
  viewer.updateText("make the visualizer crash", 50, 50, "line");
  viewer.spin();
  return 0;
}

Both text and line are added in the shape_actor_map_, so when you try to update the ID line as if it was a text, the ID is found and the SafeDownCast crashes because a vtkLODActor (line) cannot be casted into a vtkTextActor:

vtkTextActor* actor = vtkTextActor::SafeDownCast (am_it->second);

[taketwo]

I wonder why it is called safe? Perhaps it throws an exception? Then we can catch it and warn the user.

[VictorLamoine]

I can't find any documentation about this; I would have expected a NULL pointer but it throws a segfault.

[taketwo]

Are you sure that segfault occurs in down cast, not on the next line, when the pointer is used without NULL check?

[VictorLamoine]

Yup (VTK 5.8)
Uhh NO, the pointer is indeed NULL, we need to add some checks.