Message 56130 - Python tracker

The functions zlib.crc32() and zlib.adler32() return a signed value
in the range(-2147483648, 2147483648) on 32-bit platforms, but an
unsigned value in the range(0, 4294967296) on 64-bit platforms.  This
means that half the possible answers are numerically different on these
two kinds of platforms.

Ideally, this should be fixed by having them always return unsigned
numbers (their C return type is unsigned too).  It's unclear if we can
do this without breaking existing code, though :-(