};
#define REV_TREE_SAME 0
-#define REV_TREE_NEW 1
-#define REV_TREE_DIFFERENT 2
+#define REV_TREE_NEW 1 /* Only new files */
+#define REV_TREE_OLD 2 /* Only files removed */
+#define REV_TREE_DIFFERENT 3 /* Mixed changes */
/* revision.c */
void read_revisions_from_stdin(struct rev_info *revs);