Please describe the problem:
According to the documentation, when gtk_image_new_from_stock is passed a stock
id that doesn't exist, a "broken image" icon is shown in its place.  What
actually happens is that nothing appears where the GtkImage should be.  Either
the documentation is out of date and should be corrected, or the described
functionality should be implemented.

Steps to reproduce:
#include <gtk/gtk.h>
 
int main (int argc, char **argv) {
    GtkWidget *window;
    GtkWidget *image;
    GtkWidget *hbox;
 
    gtk_init(&argc, &argv);
    window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
    hbox = gtk_hbox_new(FALSE, 0);
    gtk_container_add(GTK_CONTAINER(window), hbox);
     
    image = gtk_image_new_from_stock("gtk-yes", GTK_ICON_SIZE_DIALOG);
    gtk_box_pack_start(GTK_BOX(hbox), image, FALSE, FALSE, 0);
     
    image = gtk_image_new_from_stock("yes", GTK_ICON_SIZE_DIALOG);
    gtk_box_pack_start(GTK_BOX(hbox), image, FALSE, FALSE, 0);
 
    gtk_widget_show_all(window);
    gtk_main();
}


Actual results:
Only one image is shown, the GTK_STOCK_YES icon

Expected results:
Two images should be shown, the GTK_STOCK_YES and a broken icon indicator

Does this happen every time?
Yes

Other information:
This behavior is somewhat harmless in C, as the GTK_STOCK_YES, etc, macros will
cause a compile-time failure if they don't exist.  The Gtk2-Perl bindings,
however, where I initially discovered the problem, will silently fail at
run-time, which is most confusing.  If nothing else, gtk_image_new_from_stock
should return some indicator of failure if the stock ID doesn't exist.