Subject: Re: [RFC/PATCH V2] branch.c: replace git_config with git_config_get_string

From: Tanay Abhra <[email-masked]>
Date: Thu, 26 Jun 2014 13:39:15 +0530

On 6/25/2014 10:15 AM, Eric Sunshine wrote:
> On Mon, Jun 23, 2014 at 6:41 AM, Tanay Abhra <[email-masked]> wrote:

>> diff --git a/branch.c b/branch.c
>> index 660097b..c9a2a0d 100644
>> --- a/branch.c
>> +++ b/branch.c
>> @@ -140,33 +140,25 @@ static int setup_tracking(const char *new_ref, const char *orig_ref,
>>         return 0;
>>  }
>>
>> -struct branch_desc_cb {
>> +struct branch_desc {
>>         const char *config_name;
>>         const char *value;
>>  };
> 
> What is the purpose of retaining this structure? Following your
> changes, it is never used outside of read_branch_desc(), and
> 'config_name' and 'value' would be more naturally declared as
> variables local to that function.

Done. :)

> 
>> -static int read_branch_desc_cb(const char *var, const char *value, void *cb)
>> -{
>> -       struct branch_desc_cb *desc = cb;
>> -       if (strcmp(desc->config_name, var))
>> -               return 0;
>> -       free((char *)desc->value);
>> -       return git_config_string(&desc->value, var, value);
>> -}
>> -
>>  int read_branch_desc(struct strbuf *buf, const char *branch_name)
>>  {
>> -       struct branch_desc_cb cb;
>> +       const char *value = NULL;
>> +       struct branch_desc desc;
>>         struct strbuf name = STRBUF_INIT;
>>         strbuf_addf(&name, "branch.%s.description", branch_name);
>> -       cb.config_name = name.buf;
>> -       cb.value = NULL;
>> -       if (git_config(read_branch_desc_cb, &cb) < 0) {
>> +       desc.config_name = name.buf;
>> +       desc.value = NULL;
>> +       git_config_get_string(desc.config_name, &value);
>> +       if (git_config_string(&desc.value, desc.config_name, value) < 0) {
> 
> Although it works in this case, it's somewhat ugly that you ignore the
> return value of git_config_get_string(), and a person reading the code
> has to spend extra time digging into git_config_string() to figure out
> why this is safe. If might be clearer for future readers by rephrasing
> like this:
> 
>     if (git_config_get_string(desc.config_name, &value) < 0 ||
>         git_config_string(&desc.value, desc.config_name, value) < 0) {
>

Noted, also didn't the old code leak desc.value as it was xstrduped
by git_config_string()? Thanks for the review.

>>                 strbuf_release(&name);
>>                 return -1;
>>         }
>> -       if (cb.value)
>> -               strbuf_addstr(buf, cb.value);
>> +       strbuf_addstr(buf, desc.value);
>>         strbuf_release(&name);
>>         return 0;
>>  }
>> --
>> 1.9.0.GIT
>