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>

diff --git a/builtin-rev-list.c b/builtin-rev-list.c
index fb7fc92145b6a8baec340176abf40c6b37f45a8e..4364035e154c830f7c5b2feead804b2bd33fffae 100644 (file)
--- a/builtin-rev-list.c
+++ b/builtin-rev-list.c
@@ -45,6 +45,7 @@ static int bisect_list;
 static int show_timestamp;
 static int hdr_termination;
 static const char *header_prefix;
+static int show_left_right;
 
 static void show_commit(struct commit *commit)
 {
@@ -54,6 +55,12 @@ static void show_commit(struct commit *commit)
                fputs(header_prefix, stdout);
        if (commit->object.flags & BOUNDARY)
                putchar('-');
+       else if (show_left_right) {
+               if (commit->object.flags & SYMMETRIC_LEFT)
+                       putchar('<');
+               else
+                       putchar('>');
+       }
        if (revs.abbrev_commit && revs.abbrev)
                fputs(find_unique_abbrev(commit->object.sha1, revs.abbrev),
                      stdout);
@@ -240,6 +247,10 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
                        bisect_list = 1;
                        continue;
                }
+               if (!strcmp(arg, "--left-right")) {
+                       show_left_right = 1;
+                       continue;
+               }
                if (!strcmp(arg, "--stdin")) {
                        if (read_from_stdin++)
                                die("--stdin given twice?");

diff --git a/commit.c b/commit.c
index a6d543eee7831cd6a479d4cf8b2ba81a1438b298..289ef65eb1162ff8f386bf31fa6ee27008bb3096 100644 (file)
--- a/commit.c
+++ b/commit.c
@@ -868,11 +868,11 @@ void sort_in_topological_order_fn(struct commit_list ** list, int lifo,
 
 /* merge-rebase stuff */
 
-/* bits #0..7 in revision.h */
-#define PARENT1                (1u<< 8)
-#define PARENT2                (1u<< 9)
-#define STALE          (1u<<10)
-#define RESULT         (1u<<11)
+/* bits #0..15 in revision.h */
+#define PARENT1                (1u<<16)
+#define PARENT2                (1u<<17)
+#define STALE          (1u<<18)
+#define RESULT         (1u<<19)
 
 static struct commit *interesting(struct commit_list *list)
 {

diff --git a/revision.c b/revision.c
index 993bb668a205a9fb3e2f5ddd2f378f10ac7905b4..3d989c3edf1e089d4ee9c3f4f439b1e77e2aedde 100644 (file)
--- a/revision.c
+++ b/revision.c
@@ -344,6 +344,7 @@ static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 static void add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
 {
        struct commit_list *parent = commit->parents;
+       unsigned left_flag;
 
        if (commit->object.flags & ADDED)
                return;
@@ -388,6 +389,7 @@ static void add_parents_to_list(struct rev_info *revs, struct commit *commit, st
        if (revs->no_walk)
                return;
 
+       left_flag = (commit->object.flags & SYMMETRIC_LEFT);
        parent = commit->parents;
        while (parent) {
                struct commit *p = parent->item;
@@ -395,6 +397,7 @@ static void add_parents_to_list(struct rev_info *revs, struct commit *commit, st
                parent = parent->next;
 
                parse_commit(p);
+               p->object.flags |= left_flag;
                if (p->object.flags & SEEN)
                        continue;
                p->object.flags |= SEEN;
@@ -640,7 +643,7 @@ int handle_revision_arg(const char *arg, struct rev_info *revs,
                                add_pending_commit_list(revs, exclude,
                                                        flags_exclude);
                                free_commit_list(exclude);
-                               a->object.flags |= flags;
+                               a->object.flags |= flags | SYMMETRIC_LEFT;
                        } else
                                a->object.flags |= flags_exclude;
                        b->object.flags |= flags;

diff --git a/revision.h b/revision.h
index 3adab9590a14e25c2659a1933db4af456c263a5b..f92a4d43752e02a9d1ced62b3c3c35943cb72965 100644 (file)
--- 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;