Re: [PATCH] parse-options: don't emit "ambiguous option" for aliases

> @@ -574,6 +615,70 @@ static int show_gitcomp(struct parse_opt_ctx_t *ctx,
>         return PARSE_OPT_COMPLETE;
>  }
>
> +/*
> + * Scan and may produce a new option[] array, which should be used
> + * instead of the original 'options'.
> + *
> + * Right now this is only used to preprocess and substitue
> + * OPTION_ALIAS.
> + */
> +static struct option *preprocess_options(struct parse_opt_ctx_t *ctx,
> +                                        const struct option *options)
> +{
> +       struct option *newopt;
> +       int i, nr, alias;
> +       int nr_aliases = 0;
> +
> +       for (nr = 0; options[nr].type != OPTION_END; nr++) {
> +               if (options[nr].type == OPTION_ALIAS)
> +                       nr_aliases++;
> +       }
> +
> +       if (!nr_aliases)
> +               return NULL;
> +
> +       ALLOC_ARRAY(newopt, nr + 1);
> +       COPY_ARRAY(newopt, options, nr + 1);
> +
> +       /* each alias has two string pointers and NULL */
> +       CALLOC_ARRAY(ctx->alias_groups, 3 * (nr_aliases + 1));
> +
> +       for (alias = 0, i = 0; i < nr; i++) {
> +               const char *source;
> +               int j;
> +
> +               if (newopt[i].type != OPTION_ALIAS)
> +                       continue;
> +
> +               if (!newopt[i].long_name)
> +                       BUG("An alias must have long option name");
> +
> +               source = newopt[i].value;
> +
> +               for (j = 0; j < nr; j++) {
> +                       const char *name = options[j].long_name;
> +
> +                       if (!name || strcmp(name, source))
> +                               continue;
> +
> +                       if (options[j].type == OPTION_ALIAS)
> +                               BUG("No please. Nested aliases are not supported.");
> +
> +                       memcpy(newopt + i, options + j, sizeof(*newopt));