parse-options: detect attempt to add a duplicate short option name
It is easy to overlook an already assigned single-letter option name
and try to use it for a new one. Help the developer to catch it
before such a mistake escapes the lab.
This retroactively forbids any short option name (which is defined
to be of type "int") outside the ASCII printable range. We might
want to do one of two things:
- tighten the type of short_name member to 'char', and further
update optbug() to protect it against doing "'%c'" on a funny
value, e.g. negative or above 127.
- drop the check (even the "duplicate" check) for an option whose
short_name is either negative or above 255, to allow clever folks
to take advantage of the fact that such a short_name cannot be
parsed from the command line and the member can be used to store
some extra information.
Helped-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2 files changed
