Re: [RFC] Submodules in GIT

[Sam Vilain <sam@vilain.net>]

Jakub Narebski wrote:
> I wonder if it makes sense to be able to add tag objects instead
> of commit objects to trees (depeel to tree or blob)...
>   

I'd say "as well as", and the semantics should be that to something
browsing the filesystem, a tag looks like the type of object it refers
to. eg, tag a tree, it's a tree, tag a commit, it's a sub-project/tree,
tag a blob, it's a file.

The use case I'm thinking of is semi-transparent storing of archives;
instead of storing the archive body, store a tag which contains the
"extra" information - like the gzip headers for a gz and which
compression options are needed to reproduce the same output stream. For
a tar, the per-file information such as the filestamps, owner and
permissions are recorded, and it points to a tree. A clever porcelain
could detect these file types, and make sure the uncompressed streams
are stored.

People who are using clients which don't understand these tag objects in
between will get the contents of the node checked out instead, so
instead of getting "foo.tar.gz" as a file, I got a "foo.tar.gz/" directory.