Re: [PATH/RFC] parse-options: report invalid UTF-8 switches

On Mon, Feb 11, 2013 at 09:07:53AM -0800, Junio C Hamano wrote:

Erik Faye-Lund [off-list ref] writes:

quoted

However, since git only looks at one byte at the time for
short-options, it ends up reporting a partial UTF-8 sequence
in such cases, leading to corruption of the output.

Isn't it a workable, easier and more robust alternative to punt and
use the entire ctx.argv[0] as unrecognized?

Yes, but it regresses the usability:

  [before]
  $ git foobar -qrxs
  unknown switch: x

  [after]
  $ git foobar -qrxs
  unknown switch: -qrxs

One is much more informative than the other, and you are punishing the
common ascii case for the extremely uncommon case of utf-8. Maybe:

  if (isascii(*ctx.opt))
          error("unknown option `%c'", *ctx.opt);
  else
          error("unknown multi-byte short option in string: `%s'", ctx.argv[0]);

which only kicks in in the uncommon case (and extends the error message
to make it more clear why we are showing the whole string).

-Peff