Re: [PATCH] submodule update - don't run git-fetch if sha1 available

From: Junio C Hamano <gitster@pobox.com>
Date: Aug 11, 2007, 19:44 UTC
Message-ID: <7vfy2pn9eb.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <e7bda7770708111048s77fbf416k9d0352486aee6b4a@mail.gmail.com>

"Torgil Svensson" <torgil.svensson@gmail.com> writes:

> It's un-necessary (both time-consuming and annoying if you are
> disconnected) for git submodule update to always running git-fetch
> prior to the detached head checkout of the submodule if the commit
> already exists.

This is wrong. Existence of the commit object alone does not mean the necessary tree and blob objects to check out that commit, let alone all the history that leads to the commit, exist in the repository (think of a commit walker fetch that was interrupted in the middle). You need to make sure that the commit exists *AND* is reachable from one of the refs.