SegFault on a GtkTreeSelection changed

[Nicolas Soubeiran <nicolas soubeiran gmail com>]

Hello,
I have trouble with a sorted model when deleting some row from the child
model :
the following code SegFault when you select the 2 first lines of the
treeview then click the button (remove the first line of the child model).
What should I do to avoid this

#include <gtk/gtk.h>

#define STRING_COLUMN 0
#define NB_ELEMENT 10
static  GtkWidget* _init_window( )
{
  GtkWidget* top_level =  gtk_window_new(GTK_WINDOW_TOPLEVEL);
  g_signal_connect(G_OBJECT(top_level),
           "delete-event", G_CALLBACK(gtk_main_quit), NULL);
  return top_level;
}

static GtkTreeModel* _create_sorted_model(GtkTreeModel* model)
{
  GtkTreeModel* sorted_model = gtk_tree_model_sort_new_with_model(model);
  return sorted_model;
}

void _selection_print(GtkTreeModel *model,
              GtkTreePath *path,
              GtkTreeIter *iter, gpointer data)

{
  gchar* str_data;
  gtk_tree_model_get(model, iter, STRING_COLUMN, &str_data, -1); /* SEG V */
  g_print(str_data);
  g_print("\n");
  g_free(str_data);
}

static void _print_selected_cbk (GtkTreeSelection *treeselection)
{

  if(gtk_tree_selection_count_selected_rows(treeselection) == 1)
    {
      gtk_tree_selection_selected_foreach(treeselection, _selection_print,
NULL);
    }
}

static GtkTreeModel* _create_treemodel()
{
  GtkListStore* model = gtk_list_store_new(1, G_TYPE_STRING);
  gint i;
  for(i = 0; i< NB_ELEMENT; ++i)
    {
      GtkTreeIter iter;
      const gchar* element = "element id";
      gtk_list_store_append(model, &iter);
      gtk_list_store_set(model, &iter, STRING_COLUMN, element, -1);
    }
  return GTK_TREE_MODEL(model);
}
static GtkWidget* _create_treeview(GtkTreeModel* model)
{
  GtkWidget* tree_view;
  GtkTreeSelection* selection;
  GtkCellRenderer* cell_renderer = gtk_cell_renderer_text_new();
  GtkTreeModel *sorted_model = _create_sorted_model(model);
  tree_view = gtk_tree_view_new_with_model(sorted_model);
  gtk_tree_view_insert_column_with_attributes(GTK_TREE_VIEW(tree_view), -1,
                          "name",
                          cell_renderer, "text", STRING_COLUMN, NULL);

  selection = gtk_tree_view_get_selection(GTK_TREE_VIEW(tree_view));
  gtk_tree_selection_set_mode(selection, GTK_SELECTION_MULTIPLE);

  g_signal_connect(G_OBJECT(selection),
           "changed", G_CALLBACK(_print_selected_cbk), NULL);
  return tree_view;
}

static void _delete_first_row(GtkWidget* button, GtkListStore* list)
{
  GtkTreeIter iter;
  if(gtk_tree_model_get_iter_first(GTK_TREE_MODEL(list), &iter))
    {
      gtk_list_store_remove(list, &iter);
    }
}
gint main(gint argc, gchar** argv)
{
  GtkWidget* top_level;

  GtkWidget* tree_view;
  GtkTreeModel* model;
  GtkWidget* vbox;
  GtkWidget* button;
  GtkWidget* scrolled_window;
  gtk_disable_setlocale();
  gtk_init(&argc,&argv);

  top_level = _init_window();
  model = _create_treemodel();
  tree_view = _create_treeview(model);
  button = gtk_button_new_with_label("Delete first row");
  vbox = gtk_vbox_new(5, FALSE);
  scrolled_window = gtk_scrolled_window_new(NULL, NULL);

    /* note that model is not the sorted model but its child*/
  g_signal_connect(G_OBJECT(button), "clicked",
G_CALLBACK(_delete_first_row), model);

  gtk_container_add(GTK_CONTAINER(top_level), vbox);
  gtk_box_pack_start(GTK_BOX(vbox), scrolled_window, TRUE, TRUE, 0);
  gtk_box_pack_start(GTK_BOX(vbox), button, FALSE, FALSE, 0);
  gtk_container_add(GTK_CONTAINER(scrolled_window), tree_view);

  gtk_widget_show_all(top_level);
  gtk_main();
  return 0;
};