Re: [PATCH 1/2] docs: add a basic description of the config API

From: Nguyen Thai Ngoc Duy <pclouds@gmail.com>
Date: Feb 8, 2012, 04:01 UTC
Message-ID: <CACsJy8AU3ZA1=Q3vahhP6Nr=FZNKd7oRJ04mtKVs+uvNqJeVaw@mail.gmail.com>
In-Reply-To: <7vlioe1o1g.fsf@alter.siamese.dyndns.org>

2012/2/8 Junio C Hamano <gitster@pobox.com>:

Show 20 quoted lines

> Jeff King <peff@peff.net> writes:
>
>>> > +A config callback should return 0 for success, or -1 if the variable
>>> > +could not be parsed properly.
>>>
>>> This matches what I have always thought, but I think I recently saw a
>>> series that adds callbacks that return 1 to mean "I have understood this
>>> variable, so callers should not look at it any more".  It felt wrong, but
>>> I did not find anything in the config.c API framework to prvent such a
>>> local calling convention.
>>
>> ...
>> The "1 means I understood this" convention is used by userdiff_config. I
>> don't like that it is unlike every other config callback,...
>> Looking at the code again, though, ...
>> Hmm. Yeah. The userdiff calling convention dates back to late 2008....
>> So I think we could go back and simplify the userdiff_config code now.
>
> I remembered where I saw the new "offender"; it was nd/columns
> topic (Cc'ing Nguyễn).

nd/columns does use "1" convention in git_column_config(), but the direct config callback function does not return 1 to config machinery. All call sites follow this pattern:

int ret = git_column_config(key, var, "command", &colopts); if (ret <= 0) return ret;

I think it's ok.

-- 
Duy