GtkStatusIcon leaks GDI objects when icon image is updated on Windows. If you enable blinking with gtk_status_icon_set_blinking(), the usage of GDI objects keeps increasing.

In gtkstatusicon.c::gtk_status_icon_update_image(), priv->nid.hIcon is updated to the new one, but the old one is not deleted. When gdk_win32_pixbuf_to_hicon_libgtk_only() is called, the new icon is created by CreateIconIndirect(), and it must be deleted with DestroyIcon() afterward.

The following patch fixes the leaks.

--- gtkstatusicon.c.orig        Sun Sep 10 15:33:16 2006
+++ gtkstatusicon.c     Wed Oct 25 10:59:35 2006
@@ -791,6 +791,8 @@
                                 gtk_status_icon_blank_icon (status_icon));
 #endif
 #ifdef GDK_WINDOWING_WIN32
+      if (priv->nid.hIcon)
+        DestroyIcon (priv->nid.hIcon);
       priv->nid.hIcon = gdk_win32_pixbuf_to_hicon_libgtk_only (gtk_status_icon_blank_icon (status_icon));
       priv->nid.uFlags |= NIF_ICON;
       if (priv->nid.hWnd != NULL && priv->visible)
@@ -832,6 +834,8 @@
            gtk_image_set_from_pixbuf (GTK_IMAGE (priv->image), scaled);
 #endif
 #ifdef GDK_WINDOWING_WIN32
+           if (priv->nid.hIcon)
+             DestroyIcon (priv->nid.hIcon);
            priv->nid.hIcon = gdk_win32_pixbuf_to_hicon_libgtk_only (scaled);
            priv->nid.uFlags |= NIF_ICON;
            if (priv->nid.hWnd != NULL && priv->visible)
@@ -870,6 +874,8 @@
                                    priv->image_data.stock_id,
                                    GTK_ICON_SIZE_SMALL_TOOLBAR,
                                    NULL);
+         if (priv->nid.hIcon)
+           DestroyIcon (priv->nid.hIcon);
          priv->nid.hIcon = gdk_win32_pixbuf_to_hicon_libgtk_only (pixbuf);
          priv->nid.uFlags |= NIF_ICON;
          if (priv->nid.hWnd != NULL && priv->visible)
@@ -897,6 +903,8 @@
                                      priv->size,
                                      0, NULL);
          
+         if (priv->nid.hIcon)
+           DestroyIcon (priv->nid.hIcon);
          priv->nid.hIcon = gdk_win32_pixbuf_to_hicon_libgtk_only (pixbuf);
          priv->nid.uFlags |= NIF_ICON;
          if (priv->nid.hWnd != NULL && priv->visible)