I still have remarks about traceback_unicode-3.patch, that I did not see
before:
- (a minor thing) PyMem_FREE(found_encoding) could appear only once,
just after PyFile_FromFd.
- I feel it dangerous to call the PyUnicode_AS_UNICODE() macro without
checking that PyFile_GetLine() actually returned a PyUnicode object.
- If the "truncated" variable is NULL, an exception has been set; it is
necessary to exit the function.