view tests/test-revlog.t @ 44248:12491abf93bd stable

worker: manually buffer reads from pickle stream

My previous fix (D8051, cb52e619c99e, which added Python's built-in buffering
to the pickle stream) has the problem that the selector will ignore the buffer.
When multiple pickled objects are read from the pipe into the buffer at once,
only one object will be loaded.

This can repeat until the buffer is full and delays the processing of completed
items until the worker exits, at which point the pipe is always considered
readable and all remaining items are processed.

This changeset reverts D8051, removing the buffer again. Instead, on Python 3
only, we use a wrapper to modify the "read" provided to the Unpickler to behave
more like a buffered read. We never read more bytes from the pipe than the
Unpickler requests, so the selector behaves as expected.

Also add a test case for "pickle data was truncated" issue.

https://phab.mercurial-scm.org/D8051#119193

Differential Revision: https://phab.mercurial-scm.org/D8076

  $ hg init empty-repo
  $ cd empty-repo

Flags on revlog version 0 are rejected

  >>> with open('.hg/store/00changelog.i', 'wb') as fh:
  ...     fh.write(b'\x00\x01\x00\x00') and None

  $ hg log
  abort: unknown flags (0x01) in version 0 revlog 00changelog.i!
  [255]

Unknown flags on revlog version 1 are rejected

  >>> with open('.hg/store/00changelog.i', 'wb') as fh:
  ...     fh.write(b'\x00\x04\x00\x01') and None

  $ hg log
  abort: unknown flags (0x04) in version 1 revlog 00changelog.i!
  [255]

Unknown version is rejected

  >>> with open('.hg/store/00changelog.i', 'wb') as fh:
  ...     fh.write(b'\x00\x00\x00\x02') and None

  $ hg log
  abort: unknown version (2) in revlog 00changelog.i!
  [255]

  $ cd ..

Test for CVE-2016-3630

  $ hg init

  >>> import codecs
  >>> open("a.i", "wb").write(codecs.decode(codecs.decode(
  ... b"""eJxjYGZgZIAAYQYGxhgom+k/FMx8YKx9ZUaKSOyqo4cnuKb8mbqHV5cBCVTMWb1Cwqkhe4Gsg9AD
  ... Joa3dYtcYYYBAQ8Qr4OqZAYRICPTSr5WKd/42rV36d+8/VmrNpv7NP1jQAXrQE4BqQUARngwVA==""",
  ... "base64"), "zlib")) and None

  $ hg debugrevlogindex a.i
     rev linkrev nodeid       p1           p2
       0       2 99e0332bd498 000000000000 000000000000
       1       3 6674f57a23d8 99e0332bd498 000000000000

  >>> from mercurial import revlog, vfs
  >>> tvfs = vfs.vfs(b'.')
  >>> tvfs.options = {b'revlogv1': True}
  >>> rl = revlog.revlog(tvfs, b'a.i')
  >>> rl.revision(1)
  mpatchError(*'patch cannot be decoded'*) (glob)