Fix bug #1598620: A ctypes structure cannot contain itself.

Backport from trunk.
This commit is contained in:
Thomas Heller 2006-11-24 19:00:39 +00:00
parent 0c55236d39
commit 558e56d599
3 changed files with 45 additions and 3 deletions

View File

@ -381,5 +381,35 @@ class PointerMemberTestCase(unittest.TestCase):
s.p = None
self.failUnlessEqual(s.x, 12345678)
class TestRecursiveStructure(unittest.TestCase):
def test_contains_itself(self):
class Recursive(Structure):
pass
try:
Recursive._fields_ = [("next", Recursive)]
except AttributeError, details:
self.failUnless("Structure or union cannot contain itself" in
str(details))
else:
self.fail("Structure or union cannot contain itself")
def test_vice_versa(self):
class First(Structure):
pass
class Second(Structure):
pass
First._fields_ = [("second", Second)]
try:
Second._fields_ = [("first", First)]
except AttributeError, details:
self.failUnless("_fields_ is final" in
str(details))
else:
self.fail("AttributeError not raised")
if __name__ == '__main__':
unittest.main()

View File

@ -70,6 +70,8 @@ Core and builtins
Extension Modules
-----------------
- Bug #1598620: A ctypes Structure cannot contain itself.
- Bug #1588217: don't parse "= " as a soft line break in binascii's
a2b_qp() function, instead leave it in the string as quopri.decode()
does.

View File

@ -339,14 +339,14 @@ StructUnionType_update_stgdict(PyObject *type, PyObject *fields, int isStruct)
stgdict = PyType_stgdict(type);
if (!stgdict)
return -1;
/* If this structure/union is already marked final we cannot assign
_fields_ anymore. */
if (stgdict->flags & DICTFLAG_FINAL) {/* is final ? */
PyErr_SetString(PyExc_AttributeError,
"_fields_ is final");
return -1;
}
/* XXX This should probably be moved to a point when all this
stuff is sucessfully finished. */
stgdict->flags |= DICTFLAG_FINAL; /* set final */
if (stgdict->ffi_type_pointer.elements)
PyMem_Free(stgdict->ffi_type_pointer.elements);
@ -480,5 +480,15 @@ StructUnionType_update_stgdict(PyObject *type, PyObject *fields, int isStruct)
stgdict->size = size;
stgdict->align = total_align;
stgdict->length = len; /* ADD ffi_ofs? */
/* We did check that this flag was NOT set above, it must not
have been set until now. */
if (stgdict->flags & DICTFLAG_FINAL) {
PyErr_SetString(PyExc_AttributeError,
"Structure or union cannot contain itself");
return -1;
}
stgdict->flags |= DICTFLAG_FINAL;
return MakeAnonFields(type);
}