rev-list --left-right

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>

1 files changed, 1 insertions, 0 deletions

diff --git a/revision.h b/revision.h
index 3adab9590a..f92a4d4375 100644
--- a/revision.h
+++ b/revision.h
@@ -9,6 +9,7 @@
 #define BOUNDARY	(1u<<5)
 #define BOUNDARY_SHOW	(1u<<6)
 #define ADDED		(1u<<7)	/* Parents already parsed and added? */
+#define SYMMETRIC_LEFT	(1u<<8)
 
 struct rev_info;
 struct log_info;