pythongh-99845: _PyObject_DictPointer(): fix dictoffset cast (python#99922)

vstinner · web-flow · commit 9707bf228e00 · 2022-12-01T14:07:58.000+01:00
Cast size_t to Py_ssize_t, rather than casting it to long. On 64-bit
Windows, long is 32-bit whereas Py_ssize_t is 64-bit.
diff --git a/Objects/object.c b/Objects/object.c
@@ -1076,8 +1076,9 @@ _PyObject_DictPointer(PyObject *obj)
             tsize = -tsize;
         }
         size_t size = _PyObject_VAR_SIZE(tp, tsize);
+        assert(size <= (size_t)PY_SSIZE_T_MAX);
+        dictoffset += (Py_ssize_t)size;
 
-        dictoffset += (long)size;
         _PyObject_ASSERT(obj, dictoffset > 0);
         _PyObject_ASSERT(obj, dictoffset % SIZEOF_VOID_P == 0);
     }

Original file line number	Diff line number	Diff line change
`@@ -1076,8 +1076,9 @@ _PyObject_DictPointer(PyObject *obj)`
`1076`	`1076`	`tsize = -tsize;`
`1077`	`1077`	`}`
`1078`	`1078`	`size_t size = _PyObject_VAR_SIZE(tp, tsize);`
	`1079`	`+ assert(size <= (size_t)PY_SSIZE_T_MAX);`
	`1080`	`+ dictoffset += (Py_ssize_t)size;`
`1079`	`1081`
`1080`		`- dictoffset += (long)size;`
`1081`	`1082`	`_PyObject_ASSERT(obj, dictoffset > 0);`
`1082`	`1083`	`_PyObject_ASSERT(obj, dictoffset % SIZEOF_VOID_P == 0);`
`1083`	`1084`	`}`