Junio C Hamano <gitster@xxxxxxxxx> writes:
> Sergey Organov <sorganov@xxxxxxxxx> writes:
>
>> int cmd_diff_index(int argc, const char **argv, const char *prefix)
>> {
>> struct rev_info rev;
>> unsigned int option = 0;
>> - int i;
>> int result;
>>
>> if (argc == 2 && !strcmp(argv[1], "-h"))
>> @@ -27,17 +53,16 @@ int cmd_diff_index(int argc, const char **argv, const char *prefix)
>> rev.abbrev = 0;
>> prefix = precompose_argv_prefix(argc, argv, prefix);
>>
>> + /*
>> + * It's essential to parse our distinct options before calling
>> + * setup_revisions(), for the latter not to see "-m".
>> + */
>> + argc = parse_distinct_options(argc, argv, &rev, &option);
>> argc = setup_revisions(argc, argv, &rev, NULL);
>
> This change is risky, as the loop below (which this patch moves to
> parse_distinct_options()) has no knowledge of other options that
> setup_revisions() helper is prepared to handle and that takes an
> argument. When parsing "git cmd --opt --cached A", setup_revisions()
> may know that --opt takes an argument and eat both (i.e. the
> "--cached" is not an option but an arg given to "--opt"), but the
> new parse_distinct_options() helper does not; it will happily skip
> "--opt" and leave it in, mistake "--cached" as an option and remove,
> and instead make "A" the arg given to "--opt".
>
> Picking up the remnant _after_ setup_revisions() ate what it
> understands would not have such a downside, as long as none of our
> "distinct options" take any argument.
>
> Can't we make "-m means something special for diff-index" without
> butchering the command line processing in this step? diff-index
> does not care about --diff-merges, so letting setup_revisions()
> remember only the fact that "-m" was given while parsing, and then
> postprocess what "-m" means depending on the command (i.e. everybody
> else would treat it as a short-hand for "--diff-merges=m" plus "we
> need some form of diff output, while allowing "diff-index" to treat
> it differently) should not be rocket science.
I have already considered a few ways of doing it, and what I came up
with looked least destructive to me at the moment, especially as it
broke no tests whatsoever.
I'll now re-consider my approach because of your observations, thanks!
-- Sergey Organov
