krb5_walk_realm_tree
if ((retval = krb5_walk_realm_tree(kdc_context,
r = krb5_walk_realm_tree (ctx, crealm, srealm, &cdata.tgs,
retval = krb5_walk_realm_tree(ts->ctx, krb5_princ_realm(ts->ctx, client),
krb5_error_code krb5_walk_realm_tree