add: printf (">>> Pas Possible\n");
context: gboolean categ_row_drop_possible ( GtkTreeDragDest * drag_dest, GtkTreePath * dest_path,				   GtkSelectionData * selection_data ){    if ( dest_path )    {	GtkTreeIter iter;	gint no_categ, no_sub_categ;	if ( gtk_tree_model_get_iter ( GTK_TREE_MODEL(categ_tree_model), &iter, dest_path ) )	{	    gtk_tree_model_get ( GTK_TREE_MODEL(categ_tree_model), &iter,				 CATEGORY_TREE_NO_CATEG_COLUMN, &no_categ, 				 CATEGORY_TREE_NO_SUB_CATEG_COLUMN, &no_sub_categ, 				 -1 );	    if ( no_categ != -1 && no_sub_categ != -1 )		return TRUE;	}    }    return FALSE;}