Getting list of changed objects...

I have the following tree path:

  A   C   B
  |   |
  | 3.|<--.   
  |   |   |
2.|-->'   |
  |       |
1.|------>'
  |

Where A is the root repository for my overlays. B was created by cloning A (1)

B is where development has been progressing. Finding the set of objects to move from A to B is easily obtained via:

  git-rev-list --objects B ^A 

The problem is now when I want to re-sync B with the latest version of A. What I currently do is:

Create a new C tree based on latest A (2) and then merge B back into it (3):

  git-merge-tree -m $(git-merge-base C B) C B

That works great. I now have a tree with all of the latest A code and the B changes applied. The problem is now in getting the list of objects to create the overlay repository.

  cg-log -f -r C:B

Will correctly show only those files that have actually changed between C and B in the first log entry. However, cg-log does not show me the list of tree objects that have changed between C and B.

The problem is that if I run:

  git-rev-list --objects B ^C

It shows me all of the tree and commit objects but also gives a list of all of the files that changed between A and C as if they are needed to move C to B.

Am I overlooking something, misusing things, or ?

Thanks, James