blob: c452c423a6b7680dddbe4e3f3d119fefab7348b5 (
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#!/usr/bin/env python2
import struct
import sys
import os
import argparse
def corrupt(block):
with open(block, 'r+b') as file:
# skip rev
file.read(4)
# go to last commit
tag = 0xffffffff
while True:
try:
ntag, = struct.unpack('>I', file.read(4))
except struct.error:
break
tag ^= ntag
size = (tag & 0x3ff) if (tag & 0x3ff) != 0x3ff else 0
file.seek(size, os.SEEK_CUR)
# lob off last 3 bytes
file.seek(-(size + 3), os.SEEK_CUR)
file.truncate()
def main(args):
if args.n or not args.blocks:
with open('blocks/.history', 'rb') as file:
for i in range(int(args.n or 1)):
last, = struct.unpack('<I', file.read(4))
args.blocks.append('blocks/%x' % last)
for block in args.blocks:
print 'corrupting %s' % block
corrupt(block)
if __name__ == "__main__":
parser = argparse.ArgumentParser()
parser.add_argument('-n')
parser.add_argument('blocks', nargs='*')
main(parser.parse_args())
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