longs where the top bit is set. First, change the masks so that they
are `L' longs, otherwise the sign bits will get propagated to the
result. Next, do not coerce to int before sending to pack_uint()
otherwise Python will generate an OverflowError. Here is a test
program that fails without the patch, but now succeeds:
import xdrlib
addr = (132, 151, 1, 71)
uint = 0L
for a in addr:
uint = (uint << 8) | a
ulong64 = uint << 32
p = xdrlib.Packer()
p.pack_uhyper(ulong64)
buf = p.get_buffer()
u = xdrlib.Unpacker(buf)
ulong64prime = u.unpack_uhyper()
if ulong64 == ulong64prime:
print 'okay'
else:
print 'bogus'
print ulong64, ulong64prime
data formats. The _xdr module is no longer used, since struct
supports the required IEEE floats and doubles.
(I have one doubt about not using _xdr. The struct module doesn't
handle Inf, NaN and gradual underflow correctly. If the _xdr module
does these things better, it may still have a (small) competitive
advantage. On the other hand, since not all platforms support IEEE
floating point, it's not clear that it would be a good idea to ever
transfer Inf or NaNs. Gradual underflow can be fixed in the struct
module.
Neal Norwitz
Martin v. Löwis
Skip Montanaro
Tim Peters
Fred Drake
Guido van Rossum
Barry Warsaw