merge: make mergeresult constructor initialize empty object
In future patches, we will be going to update mergeresult object
instead of building an actions dict and then setting it in the object.
Differential Revision: https://phab.mercurial-scm.org/D8819
$ 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)