--- /dev/null
+#!/usr/bin/python
+
+import sys
+import os
+import subprocess
+
+tree = sys.argv[1]
+package = os.environ['PACKAGE']
+
+p = subprocess.Popen(['git', 'ls-tree',
+ tree,
+ package],
+ stdout=subprocess.PIPE,
+ stdin=subprocess.PIPE)
+p.wait()
+t = p.stdout.read().strip().split()
+
+if t != [] and t[1] == 'tree':
+ tree = t[2]
+
+subprocess.check_call(['git', 'commit-tree',
+ tree] + sys.argv[2:],
+ stdin=sys.stdin)