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From: PJ Weisberg <pj@irregularexpressions.net>
To: Angelo Borsotti <angelo.borsotti@gmail.com>
Cc: Phil Hord <phil.hord@gmail.com>,
	Junio C Hamano <gitster@pobox.com>,
	Johannes Sixt <j.sixt@viscovery.net>, git <git@vger.kernel.org>
Subject: Re: erratic behavior commit --allow-empty
Date: Wed, 3 Oct 2012 09:06:25 -0700	[thread overview]
Message-ID: <CAJsNXTm5uhWYB+oiz=3WQQKFQ=i=+oO0L6cgGBB+2cm5BgfFCg@mail.gmail.com> (raw)
In-Reply-To: <CAB9Jk9CdYXZzPcM=YiwOUyKNQ=4uKpfs+HY7WpWBmqgQRw4SyA@mail.gmail.com>

On Wed, Oct 3, 2012 at 7:25 AM, Angelo Borsotti
<angelo.borsotti@gmail.com> wrote:
> Hi Phil,
>
>> Perhaps the confusion arises from the the meaning of "the safety".  In
>> this case, the safety mechanism in place is to prevent you from
>> creating a child commit which has the same "tree" contents (working
>> directory) as the parent commit.  It will not be the same commit
>> because it has different parent(s) than its parent commit; but the
>> tree (working directory) is the same and git normally prevents you
>> from doing this because normally this is an accident, a mistake.
>>
>> --allow-empty tells git you intend to do this and so it should bypass
>> this "no changed files" safety mechanism.  It is not a safety to
>> prevent you creating a new commit with the exact same sha1; the safety
>> is concerned only with the exact same "working directory" file
>> contents.
>>
>> Can you suggest a rewrite of this description which would make it more clear?
>
> Instead of:
>
> "Usually recording a commit that has the exact same tree as its sole
> parent commit is a mistake, and the command prevents you from making
> such a commit. This option bypasses the safety, and is primarily for
> use by foreign SCM interface scripts."
>
> I would suggest:
>
> "Usually recording a commit that has the exact same tree as its sole
> parent commit is not allowed, and the command prevents you from making
> such a commit. This option allows to disregard this condition, thereby
> making a commit even when the trees are the same. Note that when the
> tree, author, parents, message and date (with the precision of one
> second) are the same as those of an existing commit object, no new
> commit object is created, and the identity of the existing one is
> returned."

But that's true of 'git commit' generally; it has nothing to do with
--allow-empty.

-PJ

Gehm's Corollary to Clark's Law: Any technology distinguishable from
magic is insufficiently advanced.

  reply	other threads:[~2012-10-03 16:06 UTC|newest]

Thread overview: 53+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-02  7:51 erratic behavior commit --allow-empty Angelo Borsotti
2012-10-02  8:26 ` Johannes Sixt
2012-10-02  8:49   ` Angelo Borsotti
2012-10-02 17:27   ` Junio C Hamano
2012-10-02 19:34     ` Angelo Borsotti
2012-10-02 19:56       ` Junio C Hamano
2012-10-02 21:56         ` Angelo Borsotti
2012-10-03  2:10           ` PJ Weisberg
2012-10-03  5:37           ` Johannes Sixt
2012-10-03  6:22             ` Angelo Borsotti
2012-10-03  6:27               ` Johannes Sixt
     [not found]                 ` <CAB9Jk9AgtNQfWDr31CWbXf2ag=11du-aruu-0+nOZ3KaaG9=og@mail.gmail.com>
2012-10-03  7:12                   ` Johannes Sixt
2012-10-03  7:35                     ` Angelo Borsotti
2012-10-03 20:49                     ` Junio C Hamano
2012-10-03  7:29           ` Philip Oakley
2012-10-03  7:45             ` Angelo Borsotti
2012-10-03  8:04               ` Matthieu Moy
2012-10-03  8:24                 ` Angelo Borsotti
2012-10-03 11:07                   ` Matthieu Moy
2012-10-03 11:52                     ` Angelo Borsotti
     [not found]                       ` <CABURp0oHez6j8+FPG8Zm52TGVyC1XwWhE55TBDrXRGFrW6kWww@mail.gmail.com>
2012-10-03 13:35                         ` Angelo Borsotti
2012-10-03 14:15                           ` Phil Hord
2012-10-03 13:57                       ` Matthieu Moy
2012-10-03 14:46                         ` Angelo Borsotti
2012-10-03 14:52                           ` Matthieu Moy
2012-10-03 22:32                       ` Philip Oakley
2012-10-04  7:07                         ` Angelo Borsotti
2012-10-04 13:24                           ` Phil Hord
2012-10-04 19:00                             ` Angelo Borsotti
2012-10-04 21:17                           ` Philip Oakley
2012-10-04 22:09                             ` Angelo Borsotti
2012-10-04 22:42                               ` Philip Oakley
2012-10-04 23:10                                 ` Angelo Borsotti
2012-10-03 12:25                   ` Tomas Carnecky
2012-10-03 13:08                     ` Angelo Borsotti
2012-10-03 10:12               ` Andreas Schwab
2012-10-03 11:37                 ` Angelo Borsotti
2012-10-03 13:44                   ` Andreas Schwab
2012-10-03 14:37                     ` Angelo Borsotti
2012-10-03 16:44                       ` Andreas Schwab
2012-10-03 17:37                         ` Angelo Borsotti
2012-10-03 19:03                           ` Andreas Schwab
2012-10-03 19:11                             ` Angelo Borsotti
2012-10-03 20:30                               ` Andreas Schwab
2012-10-03 12:59       ` Phil Hord
2012-10-03 14:25         ` Angelo Borsotti
2012-10-03 16:06           ` PJ Weisberg [this message]
2012-10-03 17:34             ` Angelo Borsotti
2012-10-03 19:05               ` Andreas Schwab
2012-10-03 19:43               ` PJ Weisberg
2012-10-05  8:15               ` Lars Noschinski
2013-01-12 18:30   ` Jan Engelhardt
2013-01-16 12:26     ` Joachim Schmitz

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