Re: [PATCH v5 02/14] trailer: process trailers from file and arguments

From: Christian Couder <chriscool@tuxfamily.org>
Date: Feb 10, 2014, 19:59 UTC
Message-ID: <20140210.205936.813126606054805390.chriscool@tuxfamily.org>
In-Reply-To: <xmqq61omu96d.fsf@gitster.dls.corp.google.com>

From: Junio C Hamano <gitster@pobox.com>
Subject: Re: [PATCH v5 02/14] trailer: process trailers from file and arguments
Date: Mon, 10 Feb 2014 10:14:34 -0800

Show 25 quoted lines

> Christian Couder <chriscool@tuxfamily.org> writes:
> 
>> This is what "if_exists" and "if_missing" are all about.
>>
>> Either:
>>
>> 	the same key already exists regardless of the value
>>
>> and, in this case, what happens depends on what has been specified using
>> the "if_exists" configuration variable.
>>
>> Or:
>>
>> 	the same key DOES NOT already exists regardless of the value
>>
>> and in this case, what happens depends on what has been specified
>> using the "if_missing" configuration variable.
> 
> Hmm, how should things like signed-off-by be handled?  You may want
> to allow many entries with the same key with distinct values, but
> duplicated values may want to be handled differently (currently we
> only avoid to place a duplicate <key, value> consecutively, but keys
> with different semantics (e.g. "fixes-bug: #bugid") may want to say
> "unless the same key with the same value exists, append it at the
> end".

Many entries with the same key but distinct values can be configured using:

if_exists = add_if_different if_missing = add

Many entries with the same key but values that can be the same can be configured using:

if_exists = add if_missing = add

The place where the trailers are added, if they should be added, can be selected using either "where = after", the default, or "where = before".

"where = after" means just after trailers with the same key, or, if there are no trailers with the same key, after all the existing trailers.

"where = before" means just before trailers with the same key, or, if there are no trailers with the same key, before all the existing trailers.

I think that this is enough to handle most of the usual cases, but we can add other more complex options later, as I said in the last message of this thread:

http://thread.gmane.org/gmane.comp.version-control.git/237278/

Thanks, Christian.