Comment 20 for bug 121228

0x0 (NULL) is of course a valid g_list, (The empty g_list).
an empty list of found
typedef enum {
 GNOME_KEYRING_RESULT_OK,
 GNOME_KEYRING_RESULT_DENIED,
 GNOME_KEYRING_RESULT_NO_KEYRING_DAEMON,
 GNOME_KEYRING_RESULT_ALREADY_UNLOCKED,
 GNOME_KEYRING_RESULT_NO_SUCH_KEYRING,
 GNOME_KEYRING_RESULT_BAD_ARGUMENTS,
 GNOME_KEYRING_RESULT_IO_ERROR,
 GNOME_KEYRING_RESULT_CANCELLED,
 GNOME_KEYRING_RESULT_ALREADY_EXISTS
} GnomeKeyringResult;

Possible options there... do any of these actually apply in the "couldn't find the key you asked for" case?

What should it return?

A cursory glance at the (poorly documented gnome keyring code / API) suggests that finding no keys is not special cased to return a different code.