This call is the same as calling g_icon_serialize() and using the
result as the value to Menu.itemSetAttributeValue for
G_MENU_ATTRIBUTE_ICON.
This API is only intended for use with "noun" menu items; things like
bookmarks or applications in an "Open With" menu. Don't use it on
menu items corresponding to verbs (eg: stock icons for 'Save' or
'Quit').
Sets (or unsets) the icon on menu_item.
This call is the same as calling g_icon_serialize() and using the result as the value to Menu.itemSetAttributeValue for G_MENU_ATTRIBUTE_ICON.
This API is only intended for use with "noun" menu items; things like bookmarks or applications in an "Open With" menu. Don't use it on menu items corresponding to verbs (eg: stock icons for 'Save' or 'Quit').
If icon is NULL then the icon is unset.