Fix for #1303614 and #1174712:
- __dict__ descriptor abuse for subclasses of built-in types
- subclassing from both ModuleType and another built-in types
Thanks zseil for the patch.
diff --git a/Lib/test/crashers/dangerous_subclassing.py b/Lib/test/crashers/dangerous_subclassing.py
deleted file mode 100644
index 0479952..0000000
--- a/Lib/test/crashers/dangerous_subclassing.py
+++ /dev/null
@@ -1,12 +0,0 @@
-
-# http://python.org/sf/1174712
-
-import types
-
-class X(types.ModuleType, str):
- """Such a subclassing is incorrectly allowed --
- see the SF bug report for explanations"""
-
-if __name__ == '__main__':
- X('name') # segfault: ModuleType.__init__() reads
- # the dict at the wrong offset
diff --git a/Lib/test/crashers/modify_dict_attr.py b/Lib/test/crashers/modify_dict_attr.py
deleted file mode 100644
index 11c6721..0000000
--- a/Lib/test/crashers/modify_dict_attr.py
+++ /dev/null
@@ -1,20 +0,0 @@
-
-# http://python.org/sf/1303614
-
-class Y(object):
- pass
-
-class type_with_modifiable_dict(type, Y):
- pass
-
-class MyClass(object):
- """This class has its __dict__ attribute indirectly
- exposed via the __dict__ getter/setter of Y.
- """
- __metaclass__ = type_with_modifiable_dict
-
-
-if __name__ == '__main__':
- dictattr = Y.__dict__['__dict__']
- dictattr.__delete__(MyClass) # if we set tp_dict to NULL,
- print MyClass # doing anything with MyClass segfaults
diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py
index 53181ac..57cef44 100644
--- a/Lib/test/test_descr.py
+++ b/Lib/test/test_descr.py
@@ -3,6 +3,7 @@
from test.test_support import verify, vereq, verbose, TestFailed, TESTFN, get_original_stdout
from copy import deepcopy
import warnings
+import types
warnings.filterwarnings("ignore",
r'complex divmod\(\), // and % are deprecated$',
@@ -861,6 +862,16 @@
("getattr", "foo"),
("delattr", "foo")])
+ # http://python.org/sf/1174712
+ try:
+ class Module(types.ModuleType, str):
+ pass
+ except TypeError:
+ pass
+ else:
+ raise TestFailed("inheriting from ModuleType and str at the "
+ "same time should fail")
+
def multi():
if verbose: print "Testing multiple inheritance..."
class C(object):
@@ -2907,8 +2918,73 @@
cant(a, [])
cant(a, 1)
del a.__dict__ # Deleting __dict__ is allowed
- # Classes don't allow __dict__ assignment
- cant(C, {})
+
+ class Base(object):
+ pass
+ def verify_dict_readonly(x):
+ """
+ x has to be an instance of a class inheriting from Base.
+ """
+ cant(x, {})
+ try:
+ del x.__dict__
+ except (AttributeError, TypeError):
+ pass
+ else:
+ raise TestFailed, "shouldn't allow del %r.__dict__" % x
+ dict_descr = Base.__dict__["__dict__"]
+ try:
+ dict_descr.__set__(x, {})
+ except (AttributeError, TypeError):
+ pass
+ else:
+ raise TestFailed, "dict_descr allowed access to %r's dict" % x
+
+ # Classes don't allow __dict__ assignment and have readonly dicts
+ class Meta1(type, Base):
+ pass
+ class Meta2(Base, type):
+ pass
+ class D(object):
+ __metaclass__ = Meta1
+ class E(object):
+ __metaclass__ = Meta2
+ for cls in C, D, E:
+ verify_dict_readonly(cls)
+ class_dict = cls.__dict__
+ try:
+ class_dict["spam"] = "eggs"
+ except TypeError:
+ pass
+ else:
+ raise TestFailed, "%r's __dict__ can be modified" % cls
+
+ # Modules also disallow __dict__ assignment
+ class Module1(types.ModuleType, Base):
+ pass
+ class Module2(Base, types.ModuleType):
+ pass
+ for ModuleType in Module1, Module2:
+ mod = ModuleType("spam")
+ verify_dict_readonly(mod)
+ mod.__dict__["spam"] = "eggs"
+
+ # Exception's __dict__ can be replaced, but not deleted
+ class Exception1(Exception, Base):
+ pass
+ class Exception2(Base, Exception):
+ pass
+ for ExceptionType in Exception, Exception1, Exception2:
+ e = ExceptionType()
+ e.__dict__ = {"a": 1}
+ vereq(e.a, 1)
+ try:
+ del e.__dict__
+ except (TypeError, AttributeError):
+ pass
+ else:
+ raise TestFaied, "%r's __dict__ can be deleted" % e
+
def pickles():
if verbose: