> The only difference with previous code is that now OverflowError raised > for large bases instead of ValueError.

Serhiy: can you clarify this remark?  Where do you see the OverflowError? The current exception and message look fine to me, so maybe I'm misunderstanding what you're talking about:

Python 3.4.0a0 (default:1b2134a78c17, Dec 28 2012, 10:06:47) 
[GCC 4.2.1 (Apple Inc. build 5664)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> int('34', base=2**100)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: int() base must be >= 2 and <= 36
[66206 refs, 23451 blocks]

I actually think this issue can be closed as fixed:  the current code looks fine to me, and I don't think the fix should be backported.