I was debugging M2Crypto function written in C which changed behavior between Python 2.6 and earlier Python versions. In an error condition the function was supposed to raise exception type A, but with 2.6 it raised type B, and further, there was no string value for the exception.
I tracked this down to the C code incorrectly returning Py_None when it should have returned NULL. Changing the C code to return NULL made it behave correctly in 2.6. I don't know how common a mistake it is to return Py_None when NULL should have been returned, but it might be worth a note in the list of changes for 2.6 that this behavior changed, don't you think? -- Heikki Toivonen -- http://mail.python.org/mailman/listinfo/python-list
