Address SF patch #480716 as well as related issues.
SF patch #480716 by Greg Chapman fixes the problem that super's
__get__ method always returns an instance of super, even when the
instance whose __get__ method is called is an instance of a subclass
of super.
Other issues fixed:
- super(C, C()).__class__ would return the __class__ attribute of C()
rather than the __class__ attribute of the super object. This is
confusing. To fix this, I decided to change the semantics of super
so that it only applies to code attributes, not to data attributes.
After all, overriding data attributes is not supported anyway.
- While super(C, x) carefully checked that x is an instance of C,
super(C).__get__(x) made no such check, allowing for a loophole.
This is now fixed.
diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py
index 8166d7c..f3b81ac 100644
--- a/Lib/test/test_descr.py
+++ b/Lib/test/test_descr.py
@@ -1572,7 +1572,57 @@
def meth(self, a):
return "D(%r)" % a + super(D, self).meth(a)
- verify (D().meth(4) == "D(4)C(4)B(4)A(4)")
+ vereq(D().meth(4), "D(4)C(4)B(4)A(4)")
+
+ # Test for subclassing super
+
+ class mysuper(super):
+ def __init__(self, *args):
+ return super(mysuper, self).__init__(*args)
+
+ class E(D):
+ def meth(self, a):
+ return "E(%r)" % a + mysuper(E, self).meth(a)
+
+ vereq(E().meth(5), "E(5)D(5)C(5)B(5)A(5)")
+
+ class F(E):
+ def meth(self, a):
+ s = self.__super
+ return "F(%r)[%s]" % (a, s.__class__.__name__) + s.meth(a)
+ F._F__super = mysuper(F)
+
+ vereq(F().meth(6), "F(6)[mysuper]E(6)D(6)C(6)B(6)A(6)")
+
+ # Make sure certain errors are raised
+
+ try:
+ super(D, 42)
+ except TypeError:
+ pass
+ else:
+ raise TestFailed, "shouldn't allow super(D, 42)"
+
+ try:
+ super(D, C())
+ except TypeError:
+ pass
+ else:
+ raise TestFailed, "shouldn't allow super(D, C())"
+
+ try:
+ super(D).__get__(12)
+ except TypeError:
+ pass
+ else:
+ raise TestFailed, "shouldn't allow super(D).__get__(12)"
+
+ try:
+ super(D).__get__(C())
+ except TypeError:
+ pass
+ else:
+ raise TestFailed, "shouldn't allow super(D).__get__(C())"
def inherits():
if verbose: print "Testing inheritance from basic types..."