Re: [PATCH/RFC/GSOC] make git-pull a builtin

[Paul Tan <pyokagan@gmail.com>]

Hi,

On Thu, Mar 19, 2015 at 6:26 AM, Junio C Hamano <gitster@pobox.com> wrote:
> Paul Tan <pyokagan@gmail.com> writes:
>
>> +/* Global vars since they are used often */
>> +static char *head_name;
>> +static const char *head_name_short;
>> +static unsigned char head_sha1[20];
>> +static int head_flags;
>> +
>> +enum rebase_type {
>> +     REBASE_FALSE = 0,
>> +     REBASE_TRUE = 1,
>> +     REBASE_PRESERVE = 2
>> +};
>> +
>> +/**
>> + * Parse rebase config/option value and return corresponding int
>> + */
>> +static int parse_rebase(const char *arg)
>> +{
>> +     if (!strcmp(arg, "true"))
>> +             return REBASE_TRUE;
>> +     else if (!strcmp(arg, "false"))
>> +             return REBASE_FALSE;
>> +     else if (!strcmp(arg, "preserve"))
>> +             return REBASE_PRESERVE;
>> +     else
>> +             return -1; /* Invalid value */
>> +}
>
> Even though the original does not use bool-or-string-config, we
> would want to do the same by doing something like
>
>         case (config_maybe_bool()) {
>         case 0:
>                 return REBASE_FALSE;
>         case 1:
>                 return REBASE_TRUE;
>         default:
>                 if (!strcmp(arg, "preserve"))
>                         return REBASE_PRESERVE;
>                 return -1;
>         }
>
> and then use that in rebase_config_default().

If you mean letting "yes", "on", "no", "off" be accepted on the
command line as well, then yes I guess it will be a good idea.

>
>> +
>> +/**
>> + * Returns default rebase option value
>> + */
>> +static int rebase_config_default(void)
>> +{
>> +     struct strbuf name = STRBUF_INIT;
>> +     const char *value = NULL;
>> +     int boolval;
>> +
>> +     strbuf_addf(&name, "branch.%s.rebase", head_name_short);
>> +     if (git_config_get_value(name.buf, &value))
>> +             git_config_get_value("pull.rebase", &value);
>
> What happens when neither is defined?
>
>> +     strbuf_release(&name);
>> +     if (!value)
>> +             return REBASE_FALSE;
>
> Hmph, are you sure about this?  Isn't this "[pull] rebase" that does
> not have "= value", in which case pull.rebase is "true"?
>
> You cannot use NULL as the sentinel value to tell that you did not
> find either branch.*.rebase nor pull.rebase (in which case you want
> to default to 'false').  Either of them can be spelled as an
> equal-less true, which you will see as value==NULL, and you want to
> take that as 'true'.
>
>         const char *value = "false";
>         ...
>         if (get_value(..., &value))
>                 get_value(..., &value));
>         strbuf_release(&name);
>         if (!value)
>                 return REBASE_TRUE;
>         return parse_rebase(value);
>
> or something along that line, perhaps?

Whoops, didn't take into account the possibility that the config value
could be NULL. Thanks.

>
>> +     boolval = git_config_maybe_bool("pull.rebase", value);
>> +     if (boolval >= 0)
>> +             return boolval ? REBASE_TRUE : REBASE_FALSE;
>> +     else if (value && !strcmp(value, "preserve"))
>> +             return REBASE_PRESERVE;
>
> Is value something you need to free before returning from this
> function?

>From my reading if config.c, the memory of value comes from the
config_set the_config_set (the config cache), so there is no need to
free it.

>
>> +static int parse_opt_recurse_submodules(const struct option *opt, const char *arg, int unset)
>> +{
>> +     if (!arg)
>> +             *(int *)opt->value = unset ? RS_NO : RS_YES;
>> +     else if (!strcmp(arg, "no"))
>> +             *(int *)opt->value = RS_NO;
>> +     else if (!strcmp(arg, "yes"))
>> +             *(int *)opt->value = RS_YES;
>> +     else if (!strcmp(arg, "on-demand"))
>> +             *(int *)opt->value = RS_ON_DEMAND;
>> +     else
>> +             return -1;
>> +     return 0;
>
> I suspect that maybe-bool-or-string comment applies equally here for
> the UI consistency.

Yup, I'll keep that in mind.

> I'll stop here for now.  Thanks.

Thanks.