Align a tarball to a commit in a git repository

align-git.py

#!/usr/bin/env python

import os
import subprocess

# We want to reach back to a commit where the following file is identical in the tarball.
FILENAME="page_alloc.c"

# We created this file with: git log | grep '^commit' | awk '{ print $2}' > /tmp/commit-list.txt
commit_file = open("/tmp/commit-list.txt", "r")
all_commits = commit_file.readlines()

for commit in all_commits:
	subprocess.call(["git", "checkout", commit.rstrip()])
	ret = subprocess.call(["diff", FILENAME, "../../linux-3.4-sunxi/mm/" + FILENAME])
        # If this checked out version has a FILENAME file that matches the one from the tarbal,
	if ret == 0:
		print "MATCH! At commit", commit
		break