From: Junio C Hamano <gitster@pobox.com>
Date: Thu, 02 Sep 2010 01:04:28 GMT
Subject: Re: [PATCH] help.c: Pull cmd_version out of this file.
Message-ID: <7v39tt552b.fsf@alter.siamese.dyndns.org>
In-Reply-To: <AANLkTinHJHzcoFFjv-TaQ+DYVyqn46fqA802m8Lq5anp@mail.gmail.com>

Thiago Farina <tfransosi@gmail.com> writes:

>>risk causing broken builds?
> Hum, how such trivial change can cause that?

Imagine if we had this in help.c:

        int cmd_version(int argc, const char **argv, const char *prefix)
        {
                printf("git version %s\n", GIT_VERSION);
                return 0;
        }

which were compiled with this rule in Makefile:

	help.o: help.c GIT-VERSION-FILE

and then you moved the function to a new file without touching the
dependency.  Especially because the change is trivial (just moving a
function from here to there), you don't immediately notice the broken
dependency.

I just spent 15+ minutes explaining this to you (and another 10+ minutes
checking that the above is _not_ the actual case before giving the same
explanation to you last night).  Now is this still a trivial change that
costs nothing?

>>What did we gain through this exercise?  Did we fix any real problem?
> All patches should just fix real problems?

There is a "cost vs benefit" ratio you need to consider.