Use iter_commits_and_parents

ugit/cli.py

@@ -91,16 +91,13 @@ def commit(args):
 
 
 def log(args):
-    oid = args.oid
-    while oid:
+    for oid in base.iter_commits_and_parents({args.oid}):
         commit = base.get_commit(oid)
 
         print(f"commit {oid}\n")
         print(textwrap.indent(commit.message, "    "))
         print("")
 
-        oid = commit.parent
-
 
 def checkout(args):
     base.checkout(args.oid)