Comment 8 for bug 938090

Looking at this in s-c I get the "destroy" signal when the app is closed and then some event processing still happens
that causes self.icon.set_from_pixbuf() which will cause gtk_image_clear() to run on the already destroyed image
so that priv->icon_helper is NULL. This is equivalent of running:

/* run as:
 * gcc lala.c $(pkg-config --cflags --libs gtk+-x11-3.0) && ./a.out
 */
#include<gtk/gtk.h>

int main(int argc, char **argv)
{
   gtk_init(&argc, &argv);

   GtkWidget *img = gtk_image_new();
   gtk_widget_destroy(img);
   // SEGV
   gtk_image_clear(img);
}