Re: [PATCH v12 13/13] bisect--helper: `bisect_start` shell function partially in C

> On Wed, Aug 10, 2016 at 11:57 PM, Pranit Bauva <pranit.bauva@gmail.com> wrote:
>>
>> @@ -431,6 +434,244 @@ static int bisect_terms(struct bisect_terms *terms, const char **argv, int argc)
>>         return 0;
>>  }
>>
>> +static int bisect_start(struct bisect_terms *terms, int no_checkout,
>> +                       const char **argv, int argc)
>> +{
>> +       int i, has_double_dash = 0, must_write_terms = 0, bad_seen = 0;
>> +       int flags, pathspec_pos;
>> +       struct string_list revs = STRING_LIST_INIT_DUP;
>> +       struct string_list states = STRING_LIST_INIT_DUP;
>> +       struct strbuf start_head = STRBUF_INIT;
>> +       struct strbuf bisect_names = STRBUF_INIT;
>> +       struct strbuf orig_args = STRBUF_INIT;
>> +       const char *head;
>> +       unsigned char sha1[20];
>> +       FILE *fp;
>> +       struct object_id oid;
>> +
>> +       if (is_bare_repository())
>> +               no_checkout = 1;
>> +
>> +       for (i = 0; i < argc; i++) {
>> +               char *commit_id = xstrfmt("%s^{commit}", argv[i]);
>> +               if (!strcmp(argv[i], "--")) {
>> +                       has_double_dash = 1;
>> +                       break;
>> +               }
>
> In the shell code there is a loop dedicated to checking if there is a
> double dash in the arguments before the real argument parsing loop.
> There is a reason for that.
> If you do it in the same loop, has_double_dash will not be set when
> the arguments that are before the double dash will be parsed.

>> +               else if (!strcmp(argv[i], "--no-checkout"))
>> +                       no_checkout = 1;
>> +               else if (!strcmp(argv[i], "--term-good") ||
>> +                        !strcmp(argv[i], "--term-old")) {
>> +                       must_write_terms = 1;
>> +                       strbuf_reset(&terms->term_good);
>> +                       strbuf_addstr(&terms->term_good, argv[++i]);
>> +               }
>> +               else if (skip_prefix(argv[i], "--term-good=", &argv[i])) {
>
> (Maybe you could put the "else if (...) {" on the same line as the "}" above.)
>
>> +                       must_write_terms = 1;
>> +                       strbuf_reset(&terms->term_good);
>> +                       strbuf_addstr(&terms->term_good, argv[i]);
>> +               }
>> +               else if (skip_prefix(argv[i], "--term-old=", &argv[i])) {
>> +                       must_write_terms = 1;
>> +                       strbuf_reset(&terms->term_good);
>> +                       strbuf_addstr(&terms->term_good, argv[i]);
>> +               }
>> +               else if (!strcmp(argv[i], "--term-bad") ||
>> +                        !strcmp(argv[i], "--term-new")) {
>> +                       must_write_terms = 1;
>> +                       strbuf_reset(&terms->term_bad);
>> +                       strbuf_addstr(&terms->term_bad, argv[++i]);
>> +               }
>> +               else if (skip_prefix(argv[i], "--term-bad=", &argv[i])) {
>> +                       must_write_terms = 1;
>> +                       strbuf_reset(&terms->term_bad);
>> +                       strbuf_addstr(&terms->term_bad, argv[i]);
>> +               }
>> +               else if (skip_prefix(argv[i], "--term-new=", &argv[i])) {
>> +                       must_write_terms = 1;
>> +                       strbuf_reset(&terms->term_good);
>> +                       strbuf_addstr(&terms->term_good, argv[i]);
>> +               }
>> +               else if (starts_with(argv[i], "--") &&
>> +                        !one_of(argv[i], "--term-good", "--term-bad", NULL)) {
>> +                       string_list_clear(&revs, 0);
>> +                       string_list_clear(&states, 0);
>> +                       die(_("unrecognised option: '%s'"), argv[i]);
>> +               }
>> +               else if (get_oid(argv[i], &oid) && !has_double_dash) {
>
> And here checking "!has_double_dash" has no meaning if you check for a
> double dash in the same loop, because there is a "break" after
> has_double_dash is set above.

>> +                       string_list_clear(&revs, 0);
>> +                       string_list_clear(&states, 0);
>> +                       free(commit_id);
>> +                       die(_("'%s' does not appear to be a valid revision"), argv[i]);
>> +               }
>> +               else {
>> +                       free(commit_id);
>> +                       string_list_append(&revs, oid_to_hex(&oid));
>> +               }
>> +       }
>> +       pathspec_pos = i;
>> +