[Python-checkins] CVS: python/dist/src/Objects typeobject.c,2.122,2.123

[Guido van Rossum]

Update of /cvsroot/python/python/dist/src/Objects
In directory usw-pr-cvs1:/tmp/cvs-serv5060/Objects

Modified Files:
	typeobject.c 
Log Message:
Fix SF bug #489581: __slots__ leak.

It was easier than I thought, assuming that no other things contribute
to the instance size besides slots -- a pretty good bet.  With a test
suite, no less!



Index: typeobject.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Objects/typeobject.c,v
retrieving revision 2.122
retrieving revision 2.123
diff -C2 -d -r2.122 -r2.123
*** typeobject.c	2001/12/05 19:46:42	2.122
--- typeobject.c	2001/12/05 22:45:48	2.123
***************
*** 305,309 ****
  subtype_dealloc(PyObject *self)
  {
! 	PyTypeObject *type, *base;
  	destructor f;
  
--- 305,309 ----
  subtype_dealloc(PyObject *self)
  {
! 	PyTypeObject *type, *base, *temp;
  	destructor f;
  
***************
*** 315,322 ****
  	/* Find the nearest base with a different tp_dealloc */
  	type = self->ob_type;
! 	base = type->tp_base;
  	while ((f = base->tp_dealloc) == subtype_dealloc) {
  		base = base->tp_base;
  		assert(base);
  	}
  
--- 315,342 ----
  	/* Find the nearest base with a different tp_dealloc */
  	type = self->ob_type;
! 	base = type;
  	while ((f = base->tp_dealloc) == subtype_dealloc) {
+ 		temp = base;
  		base = base->tp_base;
  		assert(base);
+ 		/* While we're at it, clear __slots__ variables */
+ 		if (temp->tp_basicsize != base->tp_basicsize &&
+ 		    temp->tp_itemsize == 0)
+ 		{
+ 			char *addr = ((char *)self);
+ 			char *p = addr + base->tp_basicsize;
+ 			char *q = addr + temp->tp_basicsize;
+ 			for (; p < q; p += sizeof(PyObject *)) {
+ 				PyObject **pp;
+ 				if (p == addr + type->tp_dictoffset ||
+ 				    p == addr + type->tp_weaklistoffset)
+ 					continue;
+ 				pp = (PyObject **)p;
+ 				if (*pp != NULL) {
+ 					Py_DECREF(*pp);
+ 					*pp = NULL;
+ 				}
+ 			}
+ 		}
  	}