1 files changed, 44 insertions, 0 deletions
diff --git a/tests/corrupt.py b/tests/corrupt.py
new file mode 100755
index 0000000..44f4f66
--- /dev/null
+++ b/tests/corrupt.py
@@ -0,0 +1,44 @@
+#!/usr/bin/env python
+
+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())