Dear Maintainer,

modifying a custom starter whose icon was removed for some reason is not
possible because the starter properties dialog does not show up.

this is what appears on the command line:

$ LANG=C cinnamon-menu-editor
Gtk-Message: GtkDialog mapped without a transient parent. This is discouraged.

(cinnamon-menu-editor:3288): Gtk-WARNING **: Could not load a pixbuf from icon
theme.
This may indicate that pixbuf loaders or the mime database could not be found.
Traceback (most recent call last):
  File "/usr/share/cinnamon/cinnamon-desktop-editor/cinnamon-desktop-
editor.py", line 531, in <module>
    Main()
  File "/usr/share/cinnamon/cinnamon-desktop-editor/cinnamon-desktop-
editor.py", line 459, in __init__
    editor = LauncherEditor(self.orig_file, self.launcher_cb)
  File "/usr/share/cinnamon/cinnamon-desktop-editor/cinnamon-desktop-
editor.py", line 173, in __init__
    self.load()
  File "/usr/share/cinnamon/cinnamon-desktop-editor/cinnamon-desktop-
editor.py", line 304, in load
    self.set_icon('icon-image', "Icon")
  File "/usr/share/cinnamon/cinnamon-desktop-editor/cinnamon-desktop-
editor.py", line 238, in set_icon
    set_icon_string(self.builder.get_object(ctl), val)
  File "/usr/share/cinnamon/cinnamon-desktop-editor/cinnamon-desktop-
editor.py", line 80, in set_icon_string
    pixbuf = GdkPixbuf.Pixbuf.new_from_file_at_size(icon, 64, 64)
GLib.Error: g-file-error-quark: Failed to open file
'/usr/share/xtrkcad/html/png.d/btrain.png': No such file or directory (4)

Hi Robert,

sorry for the very long delay in answering.

This was caused by cinnamon-desktop-editor loading the icon with
GdkPixbuf.Pixbuf.new_from_file_at_size() without catching errors: when
Icon= pointed to an absolute path that no longer existed, the resulting
GLib.Error propagated out of the editor constructor and the process died
before the dialog was shown.

It was fixed upstream in Cinnamon 4.0.0, which replaced the custom icon
picker with XApp.IconChooserDialog:

https://github.com/linuxmint/cinnamon/commit/8521a3dba

The new code ignores the pixbuf loading error and simply shows an empty
icon, so the properties dialog opens normally and the Icon= value is
preserved on save.

In Debian the fix is available since cinnamon 4.0.10-1 (bullseye and
later), so I'm closing this bug.

Thanks for the report,
Fabio