Looks like this was introduced by the iOS port in commit 8993ecd06a which
changed a fatal() to a warn() which then blunders into dns_name_format()
with an invalid name.

Tony.
-- 
f.anthony.n.finch  <dot@dotat.at>  http://dotat.at/  -  I xn--zr8h punycode
North Fitzroy, Sole: Northerly or northeasterly becoming cyclonic later, 5 to
7, perhaps gale 8 later. Rough or very rough. Occasional rain. Good,
occasionally poor.