tracking perms/ownership [was: empty directories]

From: Josh England <jjengla@sandia.gov>
Date: Aug 23, 2007, 21:51 UTC
Message-ID: <1187905879.5986.199.camel@beauty>
In-Reply-To: <alpine.LFD.0.999.0708221618510.30176@woody.linux-foundation.org>

On Wed, 2007-08-22 at 16:25 -0700, Linus Torvalds wrote:

> But if .gitattributes would work, you probably could introduce both full 
> permissions and ownership rules there. We read git attributes for *other* 
> reasons when checking files out _anyway_, ie we need the CRLF attribute 
> stuff, so adding ownership attributes would not be at all odd.

So here's the initial thought. Create two new gitattributes, 'perms' and 'ownership', which will track perms/ownership for files matching the given pattern.

Looking at the index struct, it already has fields in it for file mode uid and gid (woohoo!). It looks like an addition to builtin-update-index.c could set those fields (if the gitattribute is set) the same way as how the execute bit is flipped with chmod_path(). I haven't found where the chmod is done at checkout/clone time, but the question is: If the mode, uid, and gid are stuffed in the index, will git diff simply just work to recognize permission/ownership changes? Is this the right approach? What kind of merging issues will need to be worried about?

-JE