worlds, as when the first arg (which should be the format) contains
no % conversions, and there are more args, the results are unspecified
(according to POSIX).
We can use this so the previous usage
printf -- format arg...
(which is stupid, and pointless, but used to work) continues to
simply ignore the -- (unspecified results mean we can do whatever
feels good...)
This brings back the #if 0'd block from the previous modification
(so there is no longer anything that needs cleaning up later) but runs
the getopt() loop it contained only when there are at least 2 args
(so any 1 arg printf always uses that arg as the format string,
whatever it contains, including just "--") and also only when the
first (format) arg contains no '%' characters (which guarantees no %
conversions without needing to actually parse the arg). This is the
(or a) "unspecified results" case from POSIX, so we are free to do
anything we like - including assuming that we might have options
(we don't) and pretending to process them.
8ad10c91e9