Make left-right automatic.

When using symmetric differences, I think the user almost always
would want to know which side of the symmetry each commit came
from.  So this removes --left-right option from the command
line, and turns it on automatically when a symmetric difference
is used ("git log --merge" counts as a symmetric difference
between HEAD and MERGE_HEAD).

Just in case, a new option --no-left-right is provided to defeat
this, but I do not know if it would be useful.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/revision.c b/revision.c
index d84f46e5a663a61c05354abbffaf05feee991cb6..56819f8220b379575fd0e68d970acbffd9ed0249 100644 (file)
--- a/revision.c
+++ b/revision.c
@@ -853,8 +853,8 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
                                revs->boundary = 1;
                                continue;
                        }
-                       if (!strcmp(arg, "--left-right")) {
-                               revs->left_right = 1;
+                       if (!strcmp(arg, "--no-left-right")) {
+                               revs->no_left_right = 1;
                                continue;
                        }
                        if (!strcmp(arg, "--objects")) {
@@ -1055,13 +1055,18 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 void prepare_revision_walk(struct rev_info *revs)
 {
        int nr = revs->pending.nr;
+       int has_symmetric = 0;
        struct object_array_entry *list = revs->pending.objects;
 
        revs->pending.nr = 0;
        revs->pending.alloc = 0;
        revs->pending.objects = NULL;
        while (--nr >= 0) {
-               struct commit *commit = handle_commit(revs, list->item, list->name);
+               struct commit *commit;
+
+               if (list->item->flags & SYMMETRIC_LEFT)
+                       has_symmetric = 1;
+               commit = handle_commit(revs, list->item, list->name);
                if (commit) {
                        if (!(commit->object.flags & SEEN)) {
                                commit->object.flags |= SEEN;
@@ -1073,6 +1078,8 @@ void prepare_revision_walk(struct rev_info *revs)
 
        if (revs->no_walk)
                return;
+       if (!revs->no_left_right && has_symmetric)
+               revs->left_right = 1;
        if (revs->limited)
                limit_list(revs);
        if (revs->topo_order)

diff --git a/revision.h b/revision.h
index 4585463a44c9faecdcdf4454b735b1e4ba1335aa..b2ab81488c61d320eb9017fac7ef22b52122f872 100644 (file)
--- a/revision.h
+++ b/revision.h
@@ -41,6 +41,7 @@ struct rev_info {
                        limited:1,
                        unpacked:1, /* see also ignore_packed below */
                        boundary:1,
+                       no_left_right:1,
                        left_right:1,
                        parents:1;