regex.search("((a)(?1)|(?2))", "a", flags=regex.V1) returns None incorrectly

What steps will reproduce the problem?
>>> import regex
>>> print(regex.search("((a)(?1)|(?2))", "a", flags=regex.V1))
None
>>>

What is the expected output? What do you see instead?
>>> import regex
>>> print(regex.search("((a)(?1)|(?2))", "a", flags=regex.V1))
<_regex.Match object at 0x00C0BCD0>
>>> print(regex.search("((a)(?1)|(?2))", "a", flags=regex.V1).group(0,1,2))
('a', 'a', None)
>>>

What version of the product are you using? On what operating system?
Windows XP Home SP3 (32-bit version)
Python 3.2.2 (default, Sep  4 2011, 09:51:08) [MSC v.1500 32 bit (Intel)] on win
32
regex 0.1.20120126

Please provide any additional information below.
It seems that Ver.0.1.20120123 doesn't have this issue.

Original issue reported on code.google.com by msm...@gmail.com on 28 Jan 2012 at 6:47

jamadden / mrab-regex-hg

regex.search("((a)(?1)|(?2))", "a", flags=regex.V1) returns None incorrectly #51