New issue 2378: NaN with payload in struct.(un)pack with endian-ness given https://bitbucket.org/pypy/pypy/issues/2378/nan-with-payload-in-struct-un-pa... llvtt: PyPy3 does not appear to handle NaN with a payload when calling struct.pack or struct.unpack if endianness is given as part of the format string: ``` #!python import struct # result: b'\x12\x00\x00\x00\x00\x00\xf8\x7f' struct.pack('d', struct.unpack('d', b'\x12\x00\x00\x00\x00\x00\xf8\x7f')[0]) # result: b'\x00\x00\x00\x00\x00\x00\xf8\x7f' (starts with b'\x00' instead of b'x\12') struct.pack('d', struct.unpack('<d', b'\x12\x00\x00\x00\x00\x00\xf8\x7f')[0]) ``` ``` $ pypy3 --version Python 3.2.5 (b2091e973da69152b3f928bfaabd5d2347e6df46, Sep 23 2015, 09:21:00) [PyPy 2.4.0 with GCC 4.2.1 Compatible Apple LLVM 7.0.0 (clang-700.0.72)] ``` PyPy2 does not appear to have this behavior (NaN payload is part of the output whether endian-ness is specified or not).