The output from "symmetric diff", i.e. A...B, does not
distinguish between commits that are reachable from A and the
ones that are reachable from B. In this picture, such a
symmetric diff includes commits marked with a and b.
x---b---b branch B
/ \ /
/ .
/ / \
o---x---a---a branch A
However, you cannot tell which ones are 'a' and which ones are
'b' from the output. Sometimes this is frustrating. This adds
an output option, --left-right, to rev-list.
rev-list --left-right A...B
would show ones reachable from A prefixed with '<' and the ones
reachable from B prefixed with '>'.
When combined with --boundary, boundary commits (the ones marked
with 'x' in the above picture) are shown with prefix '-', so you
would see list that looks like this:
git rev-list --left-right --boundary --pretty=oneline A...B
>
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb 3rd on b
>
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb 2nd on b
<
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa 3rd on a
<
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa 2nd on a
-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx 1st on b
-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx 1st on a
Signed-off-by: Junio C Hamano <junkio@cox.net>