Sets (or unsets) the icon on
This call is the same as calling
g_icon_serialize() and using the
result as the value to
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’).
NULL then the icon is unset.
|The data is owned by the caller of the function.|