Ok
A new patch without read1() changes.
Only one test fails, a read1() test:

======================================================================
FAIL: test_read1 (test.test_io.PyBufferedRWPairTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/lucas/Codes/python-stuff/py3k/Lib/test/test_io.py", line
1139, in test_read1
    self.assertEqual(pair.read1(3), b"abc")
AssertionError: b'a' != b'abc'


Since I've changed peek_unlocked() (which is used once by read1()), I
guess there's a problem with read1() expectations about it.