From: Jeff King <peff@peff.net>
To: Stefan Monnier <monnier@iro.umontreal.ca>
Cc: git@vger.kernel.org
Subject: Re: Can't diff against the 00000000 revision
Date: Tue, 12 Jan 2016 13:20:03 -0500 [thread overview]
Message-ID: <20160112182002.GA9244@sigill.intra.peff.net> (raw)
In-Reply-To: <jwvr3hmwz1n.fsf-monnier+gmane.comp.version-control.git@gnu.org>
On Tue, Jan 12, 2016 at 11:26:24AM -0500, Stefan Monnier wrote:
> > And hopefully that explains why "000000" does not necessarily make a
> > good placeholder for "the empty thing". There are multiple empty things,
> > and it is not clear what:
>
> > git diff 0000000 1234abcd
>
> > means. Is 0000000 a tree? A blob?
>
> Well, Git is the one who uses 000000 to refer to an empty thing, but
> indeed it seems like it does inconsistently: it's sometimes used as the
> "empty blob" and sometimes as an "empty tree".
Yes. You can think of it kind of like a NULL pointer; it just means
"nothing". So its meaning is context-dependent. The problem is if we
expect to feed it back to git in a place where the context isn't
obvious.
-Peff
next prev parent reply other threads:[~2016-01-12 18:20 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-12 15:17 Can't diff against the 00000000 revision Stefan Monnier
2016-01-12 15:32 ` Jeff King
2016-01-12 15:37 ` Jeff King
2016-01-12 16:26 ` Stefan Monnier
2016-01-12 18:20 ` Jeff King [this message]
2016-01-12 18:52 ` Junio C Hamano
2016-01-12 18:11 ` Andreas Schwab
2016-01-12 18:21 ` Jeff King
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