Implementation for: http://issues.roundup-tracker.org/issue2550731 Add mechanism for the detectors to be able to tell the source of the data changes. Support for tx_Source property on database handle. Can be used by detectors to find out the source of a change in an auditor to block changes arriving by unauthenticated mechanisms (e.g. plain email where headers can be faked). The property db.tx_Source has the following values: * None - Default value set to None. May be valid if it's a script that is created by the user. Otherwise it's an error and indicates that some code path is not properly setting the tx_Source property. * "cli" - this string value is set when using roundup-admin and supplied scripts. * "web" - this string value is set when using any web based technique: html interface, xmlrpc .... * "email" - this string value is set when using an unauthenticated email based technique. * "email-sig-openpgp" - this string value is set when email with a valid pgp signature is used. (*NOTE* the testing for this mode is incomplete. If you have a pgp infrastructure you should test and verify that this is properly set.) This also includes some (possibly incomplete) tests cases for the modes above and an example of using ts_Source in the customization.txt document.

class MockNull:
    def __init__(self, **kwargs):
        for key, value in kwargs.items():
            self.__dict__[key] = value

    def __call__(self, *args, **kwargs): return MockNull()
    def __getattr__(self, name):
        # This allows assignments which assume all intermediate steps are Null
        # objects if they don't exist yet.
        #
        # For example (with just 'client' defined):
        #
        # client.db.config.TRACKER_WEB = 'BASE/'
        self.__dict__[name] = MockNull()
        return getattr(self, name)

    def __getitem__(self, key): return self
    def __nonzero__(self): return 0
    def __str__(self): return ''
    def __repr__(self): return '<MockNull 0x%x>'%id(self)
    def gettext(self, str): return str
    _ = gettext