nsresult
nsIconChannel::Init(nsIURI* aURI)
{
  nsCOMPtr<nsIMozIconURI> iconURI = do_QueryInterface(aURI);
  NS_ASSERTION(iconURI, "URI is not an nsIMozIconURI");

  nsCAutoString stockIcon;
  iconURI->GetStockIcon(stockIcon);
  if (stockIcon.IsEmpty()) {
#ifdef MOZ_ENABLE_GNOMEUI
    return InitWithGnome(iconURI);
#else
    return NS_ERROR_NOT_AVAILABLE;
#endif
  }

  nsCAutoString iconSizeString;
  iconURI->GetIconSize(iconSizeString);

  nsCAutoString iconStateString;
  iconURI->GetIconState(iconStateString);

  GtkIconSize icon_size = moz_gtk_icon_size(iconSizeString.get());
   
  ensure_stock_image_widget();

  gboolean sensitive = strcmp(iconStateString.get(), "disabled");
  gtk_widget_set_sensitive (gStockImageWidget, sensitive);

  GdkPixbuf *icon = gtk_widget_render_icon(gStockImageWidget, stockIcon.get(),
                                           icon_size, NULL);
#if GTK_CHECK_VERSION(2,4,0)
  if (!icon) {
    ensure_icon_factory();
      
    GtkIconSet *icon_set = gtk_icon_set_new();
    GtkIconSource *icon_source = gtk_icon_source_new();
    
    gtk_icon_source_set_icon_name(icon_source, stockIcon.get());
    gtk_icon_set_add_source(icon_set, icon_source);
    gtk_icon_factory_add(gIconFactory, stockIcon.get(), icon_set);
    gtk_icon_set_unref(icon_set);
    gtk_icon_source_free(icon_source);

    icon = gtk_widget_render_icon(gStockImageWidget, stockIcon.get(),
                                  icon_size, NULL);
  }
#endif

  if (!icon)
    return NS_ERROR_NOT_AVAILABLE;
  
  nsresult rv = moz_gdk_pixbuf_to_channel(icon, iconURI,
                                          getter_AddRefs(mRealChannel));

  g_object_unref(icon);

  return rv;
}
nsresult
nsIconChannel::Init(nsIURI* aURI)
{
    nsCOMPtr<nsIMozIconURI> iconURI = do_QueryInterface(aURI);
    NS_ASSERTION(iconURI, "URI is not an nsIMozIconURI");

    nsAutoCString stockIcon;
    iconURI->GetStockIcon(stockIcon);
    if (stockIcon.IsEmpty()) {
#ifdef MOZ_ENABLE_GNOMEUI
        return InitWithGnome(iconURI);
#else
#ifdef MOZ_ENABLE_GIO
        return InitWithGIO(iconURI);
#else
        return NS_ERROR_NOT_AVAILABLE;
#endif
#endif
    }

    // Search for stockIcon
    nsAutoCString iconSizeString;
    iconURI->GetIconSize(iconSizeString);

    nsAutoCString iconStateString;
    iconURI->GetIconState(iconStateString);

    GtkIconSize icon_size = moz_gtk_icon_size(iconSizeString.get());
    GtkStateType state = iconStateString.EqualsLiteral("disabled") ?
                         GTK_STATE_INSENSITIVE : GTK_STATE_NORMAL;

    // First lookup the icon by stock id and text direction.
    GtkTextDirection direction = GTK_TEXT_DIR_NONE;
    if (StringEndsWith(stockIcon, NS_LITERAL_CSTRING("-ltr"))) {
        direction = GTK_TEXT_DIR_LTR;
    } else if (StringEndsWith(stockIcon, NS_LITERAL_CSTRING("-rtl"))) {
        direction = GTK_TEXT_DIR_RTL;
    }

    bool forceDirection = direction != GTK_TEXT_DIR_NONE;
    nsAutoCString stockID;
    bool useIconName = false;
    if (!forceDirection) {
        direction = gtk_widget_get_default_direction();
        stockID = stockIcon;
    } else {
        // GTK versions < 2.22 use icon names from concatenating stock id with
        // -(rtl|ltr), which is how the moz-icon stock name is interpreted here.
        stockID = Substring(stockIcon, 0, stockIcon.Length() - 4);
        // However, if we lookup bidi icons by the stock name, then GTK versions
        // >= 2.22 will use a bidi lookup convention that most icon themes do not
        // yet follow.  Therefore, we first check to see if the theme supports the
        // old icon name as this will have bidi support (if found).
        GtkIconTheme *icon_theme = gtk_icon_theme_get_default();
        // Micking what gtk_icon_set_render_icon does with sizes, though it's not
        // critical as icons will be scaled to suit size.  It just means we follow
        // the same pathes and so share caches.
        gint width, height;
        if (gtk_icon_size_lookup(icon_size, &width, &height)) {
            gint size = NS_MIN(width, height);
            // We use gtk_icon_theme_lookup_icon() without
            // GTK_ICON_LOOKUP_USE_BUILTIN instead of gtk_icon_theme_has_icon() so
            // we don't pick up fallback icons added by distributions for backward
            // compatibility.
            GtkIconInfo *icon =
                gtk_icon_theme_lookup_icon(icon_theme, stockIcon.get(),
                                           size, (GtkIconLookupFlags)0);
            if (icon) {
                useIconName = true;
                gtk_icon_info_free(icon);
            }
        }
    }

    ensure_stock_image_widget();
    GtkStyle *style = gtk_widget_get_style(gStockImageWidget);
    GtkIconSet *icon_set = NULL;
    if (!useIconName) {
        icon_set = gtk_style_lookup_icon_set(style, stockID.get());
    }

    if (!icon_set) {
        // Either we have choosen icon-name lookup for a bidi icon, or stockIcon is
        // not a stock id so we assume it is an icon name.
        useIconName = true;
        // Creating a GtkIconSet is a convenient way to allow the style to
        // render the icon, possibly with variations suitable for insensitive
        // states.
        icon_set = gtk_icon_set_new();
        GtkIconSource *icon_source = gtk_icon_source_new();

        gtk_icon_source_set_icon_name(icon_source, stockIcon.get());
        gtk_icon_set_add_source(icon_set, icon_source);
        gtk_icon_source_free(icon_source);
    }

    GdkPixbuf *icon =
        gtk_icon_set_render_icon (icon_set, style, direction, state,
                                  icon_size, gStockImageWidget, NULL);
    if (useIconName) {
        gtk_icon_set_unref(icon_set);
    }

    // According to documentation, gtk_icon_set_render_icon() never returns
    // NULL, but it does return NULL when we have the problem reported here:
    // https://bugzilla.gnome.org/show_bug.cgi?id=629878#c13
    if (!icon)
        return NS_ERROR_NOT_AVAILABLE;

    nsresult rv = moz_gdk_pixbuf_to_channel(icon, iconURI,
                                            getter_AddRefs(mRealChannel));

    g_object_unref(icon);

    return rv;
}