Description of problem:
bz804616 is caused by the fact that:

    status, mech, initial = self._cli.start(str(mechanisms))

returns to "initial" an empty string also for CRAM-MD5 (and DIGEST-MD5) mechanisms. While it has to return None there. See https://issues.apache.org/jira/browse/QPID-3522 for some more background.


Version-Release number of selected component (if applicable):
0.22-5.el6


How reproducible:
100%


Steps to Reproduce:
1) Execute simple python script:

from saslwrapper import Client as _Client
_cli = _Client()

mechanisms = ['CRAM-MD5', 'PLAIN']
print "supplied mechs=%s" %mechanisms
_cli.setAttr('username', 'guest')
_cli.setAttr('externaluser', 'guest')
_cli.setAttr('password', 'guest')
_cli.setAttr('host', 'localhost')
_cli.setAttr('service', 'qpidd')
status = _cli.init()
print "saslwrapper.init: status='%s'" %status
status, mech, initial = _cli.start(str(mechanisms))
print "saslwrapper.start: mech='%s', status='%s', initial='%s'" %(mech, status, initial)


Actual results:
Latest line of output is:
saslwrapper.start: mech='CRAM-MD5', status='True', initial=''


Expected results:
Latest line of output should be:
saslwrapper.start: mech='CRAM-MD5', status='True', initial='None'


Additional info:
Another reproducer: once this is fixed, python-qpid will support CRAM-MD5 mechanism, so you can test it e.g. by:

qpid-stat -q -b guest/guest@localhost:5672 --sasl-mechanism=CRAM-MD5


Be aware, EXTERNAL mechanism still requires empty string initial response