Issue1033

zlib.adler32 function computes wrong values.

This is because the data is first needlessly processed by String.getBytes,
which causes data loss due to platform character encoding issues.

Removal of the String.getBytes fixed the problem for me in zlib.py

Sorry forgot to mention Jython version: 2.2.1 release.

As pointed out by Irmen, this bug is caused by the String.getBytes call,
which encodes the string according to the platform default encoding.

The solution is to use a specific character set, like so

checksum.update(String.getBytes(s, 'iso-8859-1'))

Fix checked in at revision 4441.

If you want to patch an existing jython 2.2.1 to eliminate this problem,
then update the zlib.adler32 function to look like this

def adler32(s, value=1):
    if value != 1: 
        raise ValueError, "adler32 only support start value of 1"
    checksum = Adler32()
    checksum.update(String.getBytes(s, 'iso-8859-1'))
    return Long(checksum.getValue()).intValue()

I merged this to trunk in r4491