Re: [PATCH 3/3] Avoid doing extra 'lstat()'s for d_type if we have an up-to-date cache entry

From: Junio C Hamano <gitster@pobox.com>
Date: Jul 9, 2009, 18:37 UTC
Message-ID: <7vab3d3dpc.fsf@alter.siamese.dyndns.org>
In-Reply-To: <alpine.LFD.2.01.0907091013540.3352@localhost.localdomain>

Linus Torvalds <torvalds@linux-foundation.org> writes:

Show 18 quoted lines

> We don't really verify the whole path when we mark things ce_uptodate(). 
> Part of what read_directory() does is to find directory entries, and in 
> the process things like "git add" will notice if there's a conflict with 
> existing index entries.
>
> So if a directory has changed into a symlink to a directory, this 
> particular optimization will actually hide that, I suspect. I haven't 
> tested, though. But it might be worth-while to see what happens when you 
> had a directory structure, and then do
>
> 	mkdir dir
> 	touch dir/a
> 	touch dir/b
> 	git add dir
>
> 	mv dir new-dir
> 	ln -s new-dir dir
> 	git status

In existing codepaths, we have "has_symlink_leading_path()" checks to notice that tracked dir/[ab] have disappeared. "git diff" before or after "git status" in the above sequence does notice what you did.

Would dir/a be marked as uptodate in the index, if somebody preloads the index, after the above sequence? I hope not.