Please provide an easy way to ask "What did you just do?"

When you do an operation that changes the history, (update, pull, push to etc.) you often want
to know what just happened in your branch. It is not so easy to get this information without revision
numbers etc.

When git does an operation like this it leaves a ref named ORIG_HEAD around, so that you can use
it to specify the revision you were at, e.g. git log ORIG_HEAD.. When an operation is performed that
makes this less useful (e.g. commit), it is removed.

bzr could do something similar, for instance writing the user's current revid in to the branch config when
performing a pull, and then exposing a revision spec that provides this information, so you could do

  bzr log -r previous:..

(previous isn't that great a name, but I can't come up with a better one at the moment).

Thanks,

James