git-diff A...B to (usually) mean "git-diff `git-merge-base A B` B"

diff --git a/builtin-diff.c b/builtin-diff.c
index ae901dd25ea4d8d82752db5b28f354fd2eadfb56..efd315240f0d8434bc378bf43b866588f6f4e42e 100644 (file)
--- a/builtin-diff.c
+++ b/builtin-diff.c
@@ -285,9 +285,9 @@ int cmd_diff(int argc, const char **argv, char **envp)
                obj = deref_tag(obj, NULL, 0);
                if (!obj)
                        die("invalid object '%s' given.", name);
-               if (obj->type == TYPE_COMMIT)
+               if (obj->type == OBJ_COMMIT)
                        obj = &((struct commit *)obj)->tree->object;
-               if (obj->type == TYPE_TREE) {
+               if (obj->type == OBJ_TREE) {
                        if (ARRAY_SIZE(ent) <= ents)
                                die("more than %d trees given: '%s'",
                                    (int) ARRAY_SIZE(ent), name);
@@ -297,7 +297,7 @@ int cmd_diff(int argc, const char **argv, char **envp)
                        ents++;
                        continue;
                }
-               if (obj->type == TYPE_BLOB) {
+               if (obj->type == OBJ_BLOB) {
                        if (2 <= blobs)
                                die("more than two blobs given: '%s'", name);
                        memcpy(blob[blobs].sha1, obj->sha1, 20);
@@ -346,7 +346,15 @@ int cmd_diff(int argc, const char **argv, char **envp)
                return builtin_diff_index(&rev, argc, argv);
        else if (ents == 2)
                return builtin_diff_tree(&rev, argc, argv, ent);
+       else if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
+               /* diff A...B where there is one sane merge base between
+                * A and B.  We have ent[0] == merge-base, ent[1] == A,
+                * and ent[2] == B.  Show diff between the base and B.
+                */
+               return builtin_diff_tree(&rev, argc, argv, ent);
+       }
        else
-               return builtin_diff_combined(&rev, argc, argv, ent, ents);
+               return builtin_diff_combined(&rev, argc, argv,
+                                            ent, ents);
        usage(builtin_diff_usage);
 }