[PATCH] Fix for git-rev-list --merge-order B ^A (A,B share common base) [rev 2]

[PATCH] Fix for git-rev-list --merge-order B ^A (A,B share common base) [rev 2]

This patch makes --merge-order produce the same list as git-rev-list
without --merge-order specified.

In particular, if the graph looks like this:

A
| B
|/
C
|
D

The both git-rev-list B ^A and git-rev-list --merge-order will produce B.

The unit tests have been changed to reflect the fact that the prune
points are now formally part of the start list that is used to perform
the --merge-order sort.

That is: git-rev-list --merge-order A ^D used to produce

= A
| C

It now produces:

^ A
| C

Signed-off-by: Jon Seymour <jon.seymour@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>