Re: nicer frontend to get rebased tree?

Linus Torvalds [off-list ref] writes:

Let's look at what happens. Let's say that your history looks like

	... -> A -> B -> C -> a -> b -> c

where the upper-case letters are from the tree you track, and the 
lower-case letters are the commits you added yourself.

Now, let's say that the tree you track gets rebased, and in the process 
'B' is removed (because it turns out it was buggy), and A and C get 
modified. What happens?

You now have

	... -> A -> B -> C -> a -> b -> c     <- your branch
	  \
	    other stuff -> A' -> C'     <- newly rebased branch

(where "other stuff" is whatever the remote branch was rebased on top 
of) and when you now try to rebase your stuff on top of the newly rebased 
branch, you are going to end up trying to rebase all the _old_ commits 
that weren't even yours (ie it's going to try to rebase A, B and C too!)
...
What you can do is to basically do

	git fetch nasty-tree
	git rebase C.. --onto nasty-tree

ie you can explicitly _tell_ rebase which commits you want to rebase. 

Which if I am reading git-rebase.sh right (mind you, this is not my code,
so I may well be mistaken), that is what "pull --rebase" attempts to do
with the "oldremoteref" variable.