Index: Objects/descrobject.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Objects/descrobject.c,v
retrieving revision 2.38
diff -c -r2.38 descrobject.c
*** Objects/descrobject.c	13 Dec 2003 11:58:56 -0000	2.38
--- Objects/descrobject.c	30 Mar 2005 16:53:20 -0000
***************
*** 129,138 ****
  member_get(PyMemberDescrObject *descr, PyObject *obj, PyObject *type)
  {
  	PyObject *res;
  
  	if (descr_check((PyDescrObject *)descr, obj, &res))
  		return res;
! 	return PyMember_GetOne((char *)obj, descr->d_member);
  }
  
  static PyObject *
--- 129,152 ----
  member_get(PyMemberDescrObject *descr, PyObject *obj, PyObject *type)
  {
  	PyObject *res;
+ 	char *addr = (char*)obj;
  
  	if (descr_check((PyDescrObject *)descr, obj, &res))
  		return res;
! 	if (descr->d_member->offset < 0) {
! 		int tsize;
! 		size_t size;
! 
! 		tsize = ((PyVarObject *)obj)->ob_size;
! 		if (tsize < 0)
! 			tsize = -tsize;
! 		size = descr->d_type->tp_basicsize + tsize * descr->d_type->tp_itemsize;
! 		size = (size + (SIZEOF_VOID_P - 1)) & ~(SIZEOF_VOID_P - 1);
! 
! 		addr += (long)size;
! 		assert(addr - (char*)obj > 0);
! 	}
! 	return PyMember_GetOne(addr, descr->d_member);
  }
  
  static PyObject *
***************
*** 183,192 ****
  member_set(PyMemberDescrObject *descr, PyObject *obj, PyObject *value)
  {
  	int res;
  
  	if (descr_setcheck((PyDescrObject *)descr, obj, value, &res))
  		return res;
! 	return PyMember_SetOne((char *)obj, descr->d_member, value);
  }
  
  static int
--- 197,220 ----
  member_set(PyMemberDescrObject *descr, PyObject *obj, PyObject *value)
  {
  	int res;
+ 	char *addr = (char*)obj;
  
  	if (descr_setcheck((PyDescrObject *)descr, obj, value, &res))
  		return res;
! 	if (descr->d_member->offset < 0) {
! 		int tsize;
! 		size_t size;
! 
! 		tsize = ((PyVarObject *)obj)->ob_size;
! 		if (tsize < 0)
! 			tsize = -tsize;
! 		size = descr->d_type->tp_basicsize + tsize * descr->d_type->tp_itemsize;
! 		size = (size + (SIZEOF_VOID_P - 1)) & ~(SIZEOF_VOID_P - 1);
! 
! 		addr += (long)size;
! 		assert(addr - (char*)obj > 0);
! 	}
! 	return PyMember_SetOne(addr, descr->d_member, value);
  }
  
  static int
Index: Objects/typeobject.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Objects/typeobject.c,v
retrieving revision 2.265
diff -c -r2.265 typeobject.c
*** Objects/typeobject.c	3 Mar 2005 16:45:19 -0000	2.265
--- Objects/typeobject.c	30 Mar 2005 16:54:09 -0000
***************
*** 351,362 ****
--- 351,374 ----
  	return result;
  }
  
+ static PyTypeObject *solid_base(PyTypeObject *type);
+ 
+ static PyObject *
+ type_get_solid(PyTypeObject *type, void *context)
+ {
+ 	PyObject *result;
+ 	result = (PyObject*)solid_base(type);
+ 	Py_INCREF(result);
+ 	return result;
+ }
+ 
  static PyGetSetDef type_getsets[] = {
  	{"__name__", (getter)type_name, (setter)type_set_name, NULL},
  	{"__bases__", (getter)type_get_bases, (setter)type_set_bases, NULL},
  	{"__module__", (getter)type_module, (setter)type_set_module, NULL},
  	{"__dict__",  (getter)type_dict,  NULL, NULL},
  	{"__doc__", (getter)type_get_doc, NULL, NULL},
+ 	{"__solid__", (getter)type_get_solid, NULL, NULL},
  	{0}
  };
  
***************
*** 491,497 ****
  	for (i = 0; i < n; i++, mp++) {
  		if (mp->type == T_OBJECT_EX) {
  			char *addr = (char *)self + mp->offset;
! 			PyObject *obj = *(PyObject **)addr;
  			if (obj != NULL) {
  				int err = visit(obj, arg);
  				if (err)
--- 503,522 ----
  	for (i = 0; i < n; i++, mp++) {
  		if (mp->type == T_OBJECT_EX) {
  			char *addr = (char *)self + mp->offset;
! 			PyObject *obj;
! 			if (mp->offset < 0) {
! 				int tsize;
! 				size_t size;
! 				
! 				tsize = ((PyVarObject *)self)->ob_size;
! 				if (tsize < 0)
! 					tsize = -tsize;
! 				size = type->tp_basicsize + tsize * type->tp_itemsize;
! 				size = (size + (SIZEOF_VOID_P - 1)) & ~(SIZEOF_VOID_P - 1);
! 				
! 				addr += size;
! 			}
! 			obj = *(PyObject **)addr;
  			if (obj != NULL) {
  				int err = visit(obj, arg);
  				if (err)
***************
*** 556,562 ****
  	for (i = 0; i < n; i++, mp++) {
  		if (mp->type == T_OBJECT_EX && !(mp->flags & READONLY)) {
  			char *addr = (char *)self + mp->offset;
! 			PyObject *obj = *(PyObject **)addr;
  			if (obj != NULL) {
  				Py_DECREF(obj);
  				*(PyObject **)addr = NULL;
--- 581,600 ----
  	for (i = 0; i < n; i++, mp++) {
  		if (mp->type == T_OBJECT_EX && !(mp->flags & READONLY)) {
  			char *addr = (char *)self + mp->offset;
! 			PyObject *obj;
! 			if (mp->offset < 0) {
! 				int tsize;
! 				size_t size;
! 				
! 				tsize = ((PyVarObject *)self)->ob_size;
! 				if (tsize < 0)
! 					tsize = -tsize;
! 				size = type->tp_basicsize + tsize * type->tp_itemsize;
! 				size = (size + (SIZEOF_VOID_P - 1)) & ~(SIZEOF_VOID_P - 1);
! 				
! 				addr += size;
! 			}
! 			obj = *(PyObject **)addr;
  			if (obj != NULL) {
  				Py_DECREF(obj);
  				*(PyObject **)addr = NULL;
***************
*** 809,816 ****
  	*/
  }
  
- static PyTypeObject *solid_base(PyTypeObject *type);
- 
  /* type test with subclassing support */
  
  int
--- 847,852 ----
***************
*** 1371,1387 ****
  	size_t b_size = base->tp_basicsize;
  
  	assert(t_size >= b_size); /* Else type smaller than base! */
  	if (type->tp_itemsize || base->tp_itemsize) {
  		/* If itemsize is involved, stricter rules */
  		return t_size != b_size ||
  			type->tp_itemsize != base->tp_itemsize;
  	}
- 	if (type->tp_weaklistoffset && base->tp_weaklistoffset == 0 &&
- 	    type->tp_weaklistoffset + sizeof(PyObject *) == t_size)
- 		t_size -= sizeof(PyObject *);
- 	if (type->tp_dictoffset && base->tp_dictoffset == 0 &&
- 	    type->tp_dictoffset + sizeof(PyObject *) == t_size)
- 		t_size -= sizeof(PyObject *);
  
  	return t_size != b_size;
  }
--- 1429,1446 ----
  	size_t b_size = base->tp_basicsize;
  
  	assert(t_size >= b_size); /* Else type smaller than base! */
+ 
+ 	if (type->tp_weaklistoffset && base->tp_weaklistoffset == 0)
+ 		t_size -= sizeof(PyObject *);
+ 
+ 	if (type->tp_dictoffset && base->tp_dictoffset == 0)
+ 		t_size -= sizeof(PyObject *);
+ 
  	if (type->tp_itemsize || base->tp_itemsize) {
  		/* If itemsize is involved, stricter rules */
  		return t_size != b_size ||
  			type->tp_itemsize != base->tp_itemsize;
  	}
  
  	return t_size != b_size;
  }
***************
*** 1461,1468 ****
  	assert(obj->ob_type->tp_weaklistoffset > 0);
  	assert(obj->ob_type->tp_weaklistoffset + sizeof(PyObject *) <=
  	       (size_t)(obj->ob_type->tp_basicsize));
! 	weaklistptr = (PyObject **)
! 		((char *)obj + obj->ob_type->tp_weaklistoffset);
  	if (*weaklistptr == NULL)
  		result = Py_None;
  	else
--- 1520,1526 ----
  	assert(obj->ob_type->tp_weaklistoffset > 0);
  	assert(obj->ob_type->tp_weaklistoffset + sizeof(PyObject *) <=
  	       (size_t)(obj->ob_type->tp_basicsize));
! 	weaklistptr = PyObject_GetWeakrefsListptr(obj);
  	if (*weaklistptr == NULL)
  		result = Py_None;
  	else
***************
*** 1562,1568 ****
  	PyHeapTypeObject *et;
  	PyMemberDef *mp;
  	int i, nbases, nslots, slotoffset, add_dict, add_weak;
! 	int j, may_add_dict, may_add_weak;
  
  	assert(args != NULL && PyTuple_Check(args));
  	assert(kwds == NULL || PyDict_Check(kwds));
--- 1620,1626 ----
  	PyHeapTypeObject *et;
  	PyMemberDef *mp;
  	int i, nbases, nslots, slotoffset, add_dict, add_weak;
! 	int j, may_add_dict, may_add_weak, delta;
  
  	assert(args != NULL && PyTuple_Check(args));
  	assert(kwds == NULL || PyDict_Check(kwds));
***************
*** 1657,1663 ****
  	add_dict = 0;
  	add_weak = 0;
  	may_add_dict = base->tp_dictoffset == 0;
! 	may_add_weak = base->tp_weaklistoffset == 0 && base->tp_itemsize == 0;
  	if (slots == NULL) {
  		if (may_add_dict) {
  			add_dict++;
--- 1715,1721 ----
  	add_dict = 0;
  	add_weak = 0;
  	may_add_dict = base->tp_dictoffset == 0;
! 	may_add_weak = base->tp_weaklistoffset == 0;
  	if (slots == NULL) {
  		if (may_add_dict) {
  			add_dict++;
***************
*** 1682,1692 ****
  
  		/* Are slots allowed? */
  		nslots = PyTuple_GET_SIZE(slots);
! 		if (nslots > 0 && base->tp_itemsize != 0) {
! 			PyErr_Format(PyExc_TypeError,
! 				     "nonempty __slots__ "
! 				     "not supported for subtype of '%s'",
! 				     base->tp_name);
  		  bad_slots:
  			Py_DECREF(bases);
  			Py_DECREF(slots);
--- 1740,1746 ----
  
  		/* Are slots allowed? */
  		nslots = PyTuple_GET_SIZE(slots);
! 		if (0) {
  		  bad_slots:
  			Py_DECREF(bases);
  			Py_DECREF(slots);
***************
*** 1886,1892 ****
  
  	/* Add descriptors for custom slots from __slots__, or for __dict__ */
  	mp = PyHeapType_GET_MEMBERS(et);
! 	slotoffset = base->tp_basicsize;
  	if (slots != NULL) {
  		for (i = 0; i < nslots; i++, mp++) {
  			mp->name = PyString_AS_STRING(
--- 1940,1953 ----
  
  	/* Add descriptors for custom slots from __slots__, or for __dict__ */
  	mp = PyHeapType_GET_MEMBERS(et);
! 	if (base->tp_itemsize) {
! 		slotoffset = -sizeof(PyObject*);
! 		delta = -sizeof(PyObject*);
! 	}
! 	else {
! 		slotoffset = base->tp_basicsize;
! 		delta = sizeof(PyObject*);
! 	}
  	if (slots != NULL) {
  		for (i = 0; i < nslots; i++, mp++) {
  			mp->name = PyString_AS_STRING(
***************
*** 1900,1921 ****
  				mp->flags = READONLY;
  				type->tp_weaklistoffset = slotoffset;
  			}
! 			slotoffset += sizeof(PyObject *);
  		}
  	}
  	if (add_dict) {
! 		if (base->tp_itemsize)
! 			type->tp_dictoffset = -(long)sizeof(PyObject *);
  		else
  			type->tp_dictoffset = slotoffset;
! 		slotoffset += sizeof(PyObject *);
  	}
  	if (add_weak) {
! 		assert(!base->tp_itemsize);
! 		type->tp_weaklistoffset = slotoffset;
! 		slotoffset += sizeof(PyObject *);
  	}
- 	type->tp_basicsize = slotoffset;
  	type->tp_itemsize = base->tp_itemsize;
  	type->tp_members = PyHeapType_GET_MEMBERS(et);
  
--- 1961,1998 ----
  				mp->flags = READONLY;
  				type->tp_weaklistoffset = slotoffset;
  			}
! 			slotoffset += delta;
  		}
  	}
  	if (add_dict) {
! 		if (base->tp_itemsize) {
! 			if (add_weak)
! 				type->tp_dictoffset = -2*(long)sizeof(PyObject *);
! 			else
! 				type->tp_dictoffset = -(long)sizeof(PyObject *);
! 		}
  		else
  			type->tp_dictoffset = slotoffset;
! 		slotoffset += delta;
! 	}
! 	else {
! 		if (add_weak && base->tp_itemsize && base->tp_dictoffset < 0)
! 			type->tp_dictoffset = base->tp_dictoffset - (long)sizeof(PyObject *);
  	}
  	if (add_weak) {
! 		if (base->tp_itemsize) {
! 			type->tp_weaklistoffset = -(long)sizeof(PyObject *);
! 		}
! 		else
! 			type->tp_weaklistoffset = slotoffset;
! 		slotoffset += delta;
! 	}
! 	if (base->tp_itemsize) {
! 		type->tp_basicsize = base->tp_basicsize - slotoffset - 4;
! 	}
! 	else {
! 		type->tp_basicsize = slotoffset;
  	}
  	type->tp_itemsize = base->tp_itemsize;
  	type->tp_members = PyHeapType_GET_MEMBERS(et);
  
Index: Objects/weakrefobject.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Objects/weakrefobject.c,v
retrieving revision 1.21
diff -c -r1.21 weakrefobject.c
*** Objects/weakrefobject.c	27 Mar 2005 03:04:54 -0000	1.21
--- Objects/weakrefobject.c	30 Mar 2005 16:54:20 -0000
***************
*** 846,851 ****
--- 846,878 ----
      return PyWeakref_GET_OBJECT(ref);
  }
  
+ PyObject **
+ PyObject_GetWeakrefsListptr(PyObject *obj)
+ {
+     long weaklistoffset;
+     PyTypeObject *tp = obj->ob_type;
+ 
+     if (!(tp->tp_flags & Py_TPFLAGS_HAVE_WEAKREFS))
+         return NULL;
+     weaklistoffset = tp->tp_weaklistoffset;
+     if (weaklistoffset == 0)
+         return NULL;
+     if (weaklistoffset < 0) {
+         int tsize;
+         size_t size;
+ 
+         tsize = ((PyVarObject *)obj)->ob_size;
+         if (tsize < 0)
+             tsize = -tsize;
+         size = _PyObject_VAR_SIZE(tp, tsize);
+ 
+         weaklistoffset += (long)size;
+         assert(weaklistoffset > 0);
+         assert(weaklistoffset % SIZEOF_VOID_P == 0);
+     }
+     return (PyObject **) ((char *)obj + weaklistoffset);
+ }
+ 
  /* Note that there's an inlined copy-paste of handle_callback() in gcmodule.c's
   * handle_weakrefs().
   */
Index: Include/objimpl.h
===================================================================
RCS file: /cvsroot/python/python/dist/src/Include/objimpl.h,v
retrieving revision 2.60
diff -c -r2.60 objimpl.h
*** Include/objimpl.h	15 Jul 2004 04:05:59 -0000	2.60
--- Include/objimpl.h	30 Mar 2005 16:54:22 -0000
***************
*** 329,338 ****
  /* Test if a type supports weak references */
  #define PyType_SUPPORTS_WEAKREFS(t) \
          (PyType_HasFeature((t), Py_TPFLAGS_HAVE_WEAKREFS) \
!          && ((t)->tp_weaklistoffset > 0))
  
  #define PyObject_GET_WEAKREFS_LISTPTR(o) \
! 	((PyObject **) (((char *) (o)) + (o)->ob_type->tp_weaklistoffset))
  
  #ifdef __cplusplus
  }
--- 329,341 ----
  /* Test if a type supports weak references */
  #define PyType_SUPPORTS_WEAKREFS(t) \
          (PyType_HasFeature((t), Py_TPFLAGS_HAVE_WEAKREFS) \
!          && ((t)->tp_weaklistoffset != 0))
! 
! PyAPI_FUNC(PyObject **) PyObject_GetWeakrefsListptr(PyObject *);
  
  #define PyObject_GET_WEAKREFS_LISTPTR(o) \
! 	PyObject_GetWeakrefsListptr(o)
! 
  
  #ifdef __cplusplus
  }
Index: Lib/test/test_descr.py
===================================================================
RCS file: /cvsroot/python/python/dist/src/Lib/test/test_descr.py,v
retrieving revision 1.204
diff -c -r1.204 test_descr.py
*** Lib/test/test_descr.py	3 Mar 2005 16:45:19 -0000	1.204
--- Lib/test/test_descr.py	30 Mar 2005 16:54:59 -0000
***************
*** 1907,1912 ****
--- 1928,1953 ----
      del yes
      verify(r() is None)
      del r
+     
+     # object is not a variable sized type, str is
+     for base in object, str:
+         # acquire the weakref slot in different orders:
+         class A(base):
+             pass
+         class _B(base):
+             __slots__ = ['__weakref__']
+         class B(_B):
+             __slots__ = ['__dict__']
+         class _C(base):
+             __slots__ = ['__dict__']
+         class C(_C):
+             __slots__ = ['__weakref__']
+         for cls in A, B, C:
+             inst = cls()
+             r = weakref.ref(inst)
+             verify(r() is inst)
+             del inst
+             verify(r() is None)
  
  def properties():
      if verbose: print "Testing property..."