STINNER Victor wrote:
> 
> STINNER Victor <victor.stinner@haypocalc.com> added the comment:
> 
>> I also found out that, according to RFC 3629, surrogates 
>> are considered invalid and they can't be encoded/decoded, 
>> but the UTF-8 codec actually does it.
> 
> Python2 does, but Python3 raises an error.
> 
> Python 2.7a4+ (trunk:79675, Apr  3 2010, 16:11:36)
>>>> u"\uDC80".encode("utf8")
> '\xed\xb2\x80'
> 
> Python 3.2a0 (py3k:79441, Mar 26 2010, 13:04:55)
>>>> "\uDC80".encode("utf8")
> UnicodeEncodeError: 'utf-8' codec can't encode character '\udc80' in position 0: surrogates not allowed
> 
> Deny encoding surrogates (in utf8) causes a lot of crashs in Python3, because most functions calling suppose that _PyUnicode_AsString() does never fail: see #6687 (and #8195 and a lot of other crashs). It's not a good idea to change it in Python 2.7, because it would require a huge work and we are close to the first beta of 2.7.

I wonder how that change got into the 3.x branch - I would certainly
not have approved it for the reasons given further up on this ticket.

I think we should revert that change for Python 3.2.