view roundup/anypy/cmp_.py @ 5548:fea11d05110e

Avoid errors from selecting "no selection" on multilink (issue2550722). As discussed in issue 2550722 there are various cases where selecting "no selection" on a multilink can result in inappropriate errors from Roundup: * If selecting "no selection" produces a null edit (a value was set in the multilink in an edit with an error, then removed again, along with all other changes, in the next form submission), so the page is rendered from the form contents including the "-<id>" value for "no selection" for the multilink. * If creating an item with a nonempty value for a multilink has an error, and the resubmission changes that multilink to "no selection" (and this in turn has subcases, according to whether the creation then succeeds or fails on the resubmission, which need fixes in different places in the Roundup code). All of these cases have in common that it is expected and OK to have a "-<id>" value for a submission for a multilink when <id> is not set in that multilink in the database (because the original attempt to set <id> in that multilink had an error), so the hyperdb.py logic to give an error in that case is thus removed. In the subcase of the second case where the resubmission with "no selection" has an error, the templating code tries to produce a menu entry for the "-<id>" multilink value, which also results in an error, hence the templating.py change to ignore such values in the list for a multilink.
author Joseph Myers <jsm@polyomino.org.uk>
date Thu, 27 Sep 2018 11:33:01 +0000
parents 9a09719b0d8e
children 142553f58694
line wrap: on
line source

try:
    None < 0
    def NoneAndDictComparable(v):
        return v
except TypeError:
    # comparator to allow comparisons against None and dict
    # comparisons (these were allowed in Python 2, but aren't allowed
    # in Python 3 any more)
    class NoneAndDictComparable(object):
        def __init__(self, value):
            self.value = value

        def __cmp__(self, other):
            if not isinstance(other, self.__class__):
                raise TypeError('not comparable')

            if self.value == other.value:
                return 0

            elif self.value is None:
                return -1

            elif other.value is None:
                return 1

            elif type(self.value) == tuple and type(other.value) == tuple:
                for lhs, rhs in zip(self.value, other.value):
                    lhsCmp = NoneAndDictComparable(lhs)
                    rhsCmp = NoneAndDictComparable(rhs)
                    result = lhsCmp.__cmp__(rhsCmp)
                    if result != 0:
                        return result

                return len(self.value) - len(other.value)

            elif type(self.value) == dict and type(other.value) == dict:
                diff = len(self.value) - len(other.value)
                if diff == 0:
                    lhsItems = tuple(sorted(self.value.items(),
                                            key=NoneAndDictComparable))
                    rhsItems = tuple(sorted(other.value.items(),
                                            key=NoneAndDictComparable))
                    return -1 if NoneAndDictComparable(lhsItems) < NoneAndDictComparable(rhsItems) else 1
                else:
                    return diff

            elif self.value < other.value:
                return -1

            else:
                return 1

        def __eq__(self, other):
            return self.__cmp__(other) == 0
        def __ne__(self, other):
            return self.__cmp__(other) != 0
        def __lt__(self, other):
            return self.__cmp__(other) < 0
        def __le__(self, other):
            return self.__cmp__(other) <= 0
        def __ge__(self, other):
            return self.__cmp__(other) >= 0
        def __gt__(self, other):
            return self.__cmp__(other) > 0

def _test():
    Comp = NoneAndDictComparable

    assert Comp(None) < Comp(0)
    assert Comp(None) < Comp('')
    assert Comp(None) < Comp({})
    assert Comp((0, None)) < Comp((0, 0))
    assert not Comp(0) < Comp(None)
    assert not Comp('') < Comp(None)
    assert not Comp({}) < Comp(None)
    assert not Comp((0, 0)) < Comp((0, None))

    assert Comp((0, 0)) < Comp((0, 0, None))
    assert Comp((0, None, None)) < Comp((0, 0, 0))

    assert Comp(0) < Comp(1)
    assert Comp(1) > Comp(0)
    assert not Comp(1) < Comp(0)
    assert not Comp(0) > Comp(0)

    assert Comp({ 0: None }) < Comp({ 0: 0 })
    assert Comp({ 0: 0 }) < Comp({ 0: 1 })

    assert Comp({ 0: 0 }) == Comp({ 0: 0 })
    assert Comp({ 0: 0 }) != Comp({ 0: 1 })
    assert Comp({ 0: 0, 1: 1 }) > Comp({ 0: 1 })
    assert Comp({ 0: 0, 1: 1 }) < Comp({ 0: 0, 2: 2 })

if __name__ == '__main__':
    _test()

Roundup Issue Tracker: http://roundup-tracker.org/