Empty bundles are not useless

["R. Lemos" <rslemos@gmail.com>]

When working disconnected (sending bundles back and forth) it is
useful to make bundles like this:

$ git bundle create /tmp/my.bundle master ^disconnected/master

This way I pack all new commits since the last updated from
`disconnected` remote.

But if my local copy is up-to-date, git bundle refuses to create an
empty bundle, since there are no commits to send.

However it would be nice to at least send the information that my
local branch `master` is up-to-date. That is, the bundle would just
convey that my local `master` points to a given commit (even though
this commit is already on the remote site). This way, when I upload
this bundle to the remote site, then bring back changes made there,
the remote site will know which commits I already have.

Thanks.
Rodrigo Lemos