Re: (unknown)

From: Linus Torvalds <torvalds@osdl.org>
Date: Oct 26, 2006, 15:35 UTC
Message-ID: <Pine.LNX.4.64.0610260825040.3962@g5.osdl.org>
In-Reply-To: <200610261522.44433.Josef.Weidendorfer@gmx.de>

On Thu, 26 Oct 2006, Josef Weidendorfer wrote:

Show 8 quoted lines

> On Thursday 26 October 2006 00:20, Junio C Hamano wrote:
> > Heh, I spoke too fast.
> > 
> > 	"git log origin..master"
> > 
> > If you do not have none of .git/origin
> 
> Really? I thought refs are always looked up in ".git/refs" only?

Yes and no.

The "iterate over all refs" code only ever looks in the "refs" subdirectory, so when you _list_ refs, they won't ever be shown unless they are there. That affects a lot of programs (like "git ls-remote").

Also, a symlink-ref has to point into "refs/" or it is considered invalid.

But, there are two extra rules:

 - ".git/HEAD" is obviously special, and will show up separately even for 
   things like "git ls-remote", so even processes that _list_ things will 
   show it.

 - when you do a named lookup, stuff directly in ".git" will take 
   precedence over EVERYTHING, even if it is never listed. So for example, 
   if you have a branch named HEAD in .git/refs/heads/HEAD, it doesn't 
   matter. Your ".git/HEAD" will still be looked up first.

   Similarly, other "special heads", like ORIG_HEAD or MERGE_HEAD will be 
   looked up in .git, even though they will never be listed by anything.

So the "refs/" requirement is a real requirement for a "true ref", but it is still overruled by the rule that we have special refs in $GIT_DIR that always take precedence.

This also means, for example, that you can always give the "full" refname for lookup, ie

	git-rev-parse refs/heads/master

works, because that's the "full path" from the ".git" subdirectory. If we only ever looked things up inside "refs", you'd have to use "heads/master".