bug#33468: A bug with yes and --help

[Eric Blake]

On 2/19/19 2:24 AM, Bernhard Voelker wrote:
> On 2/18/19 11:20 AM, Assaf Gordon wrote:
>> [...] what do you think ?
> 
> Thanks for driving this.
> 
> To Eric's suggestion, I'd remove the RESET_OPTIND function argument,
> because it's never used.
> Re. OPTIND: what about resetting the values of all involved externals
> to their previous value?
> 
> +  int saved_opterr = opterr;
> +  int saved_optind = optind;
> +  int saved_optopt = optopt;
> +  char *saved_optarg = optarg;
> 
> ...
> 
> +  /* Restore previous values.  */
> +  opterr = saved_opterr;
> +  optind = saved_optind;
> +  optopt = saved_optopt;
> +  optarg = saved_optarg;

Why? Most callers call this _instead_ of getopt_long(), so they don't
care what things are left at except that optind must point to the first
non-option.  Restoring optind (to 1) is wrong.  And for the rare caller
that DOES want to call getopt_long() themselves afterwards, they can
safe/restore as needed prior to calling this helper.  Restoring state
made sense as long as we had a RESET_OPTIND argument, but now I'm
thinking that it does not buy us any utility at all - just blindly set
opterr without worrying about restoring it.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
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