[Python-checkins] r58893 - in python/trunk: Doc/library/marshal.rst Lib/test/test_marshal.py Misc/NEWS Python/marshal.c

Guido van Rossum guido at python.org
Wed Nov 7 02:17:50 CET 2007


Thanks for fixing this! Though I wouldn't necessarily consider it a
backport candidate, since IIUC it can also cause errors to be raised
in code that used to work (and to some apps the "subclassiness" may
not be that important).

--Guido

On 11/6/07, raymond.hettinger <python-checkins at python.org> wrote:
> Author: raymond.hettinger
> Date: Wed Nov  7 02:13:09 2007
> New Revision: 58893
>
> Modified:
>    python/trunk/Doc/library/marshal.rst
>    python/trunk/Lib/test/test_marshal.py
>    python/trunk/Misc/NEWS
>    python/trunk/Python/marshal.c
> Log:
> Fix marshal's incorrect handling of subclasses of builtin types (backport candidate).
>
> Modified: python/trunk/Doc/library/marshal.rst
> ==============================================================================
> --- python/trunk/Doc/library/marshal.rst        (original)
> +++ python/trunk/Doc/library/marshal.rst        Wed Nov  7 02:13:09 2007
> @@ -45,12 +45,6 @@
>  (they will cause infinite loops).
>
>  .. warning::
> -
> -   Some unsupported types such as subclasses of builtins will appear to marshal
> -   and unmarshal correctly, but in fact, their type will change and the
> -   additional subclass functionality and instance attributes will be lost.
> -
> -.. warning::
>
>     On machines where C's ``long int`` type has more than 32 bits (such as the
>     DEC Alpha), it is possible to create plain Python integers that are longer
>
> Modified: python/trunk/Lib/test/test_marshal.py
> ==============================================================================
> --- python/trunk/Lib/test/test_marshal.py       (original)
> +++ python/trunk/Lib/test/test_marshal.py       Wed Nov  7 02:13:09 2007
> @@ -244,6 +244,17 @@
>          last.append([0])
>          self.assertRaises(ValueError, marshal.dumps, head)
>
> +    def test_exact_type_match(self):
> +        # Former bug:
> +        #   >>> class Int(int): pass
> +        #   >>> type(loads(dumps(Int())))
> +        #   <type 'int'>
> +        for typ in (int, long, float, complex, tuple, list, dict, set, frozenset):
> +            # Note: str and unicode sublclasses are not tested because they get handled
> +            # by marshal's routines for objects supporting the buffer API.
> +            subtyp = type('subtyp', (typ,), {})
> +            self.assertRaises(ValueError, marshal.dumps, subtyp())
> +
>  def test_main():
>      test_support.run_unittest(IntTestCase,
>                                FloatTestCase,
>
> Modified: python/trunk/Misc/NEWS
> ==============================================================================
> --- python/trunk/Misc/NEWS      (original)
> +++ python/trunk/Misc/NEWS      Wed Nov  7 02:13:09 2007
> @@ -812,6 +812,10 @@
>  Extension Modules
>  -----------------
>
> +- Marshal.dumps() now expects exact type matches for int, long, float, complex,
> +  tuple, list, dict, set, and frozenset.  Formerly, it would silently miscode
> +  subclasses of those types.  Now, it raises a ValueError instead.
> +
>  - Patch #1388440: Add set_completion_display_matches_hook and
>    get_completion_type to readline.
>
>
> Modified: python/trunk/Python/marshal.c
> ==============================================================================
> --- python/trunk/Python/marshal.c       (original)
> +++ python/trunk/Python/marshal.c       Wed Nov  7 02:13:09 2007
> @@ -144,7 +144,7 @@
>         else if (v == Py_True) {
>                 w_byte(TYPE_TRUE, p);
>         }
> -       else if (PyInt_Check(v)) {
> +       else if (PyInt_CheckExact(v)) {
>                 long x = PyInt_AS_LONG((PyIntObject *)v);
>  #if SIZEOF_LONG > 4
>                 long y = Py_ARITHMETIC_RIGHT_SHIFT(long, x, 31);
> @@ -159,7 +159,7 @@
>                         w_long(x, p);
>                 }
>         }
> -       else if (PyLong_Check(v)) {
> +       else if (PyLong_CheckExact(v)) {
>                 PyLongObject *ob = (PyLongObject *)v;
>                 w_byte(TYPE_LONG, p);
>                 n = ob->ob_size;
> @@ -169,7 +169,7 @@
>                 for (i = 0; i < n; i++)
>                         w_short(ob->ob_digit[i], p);
>         }
> -       else if (PyFloat_Check(v)) {
> +       else if (PyFloat_CheckExact(v)) {
>                 if (p->version > 1) {
>                         unsigned char buf[8];
>                         if (_PyFloat_Pack8(PyFloat_AsDouble(v),
> @@ -190,7 +190,7 @@
>                 }
>         }
>  #ifndef WITHOUT_COMPLEX
> -       else if (PyComplex_Check(v)) {
> +       else if (PyComplex_CheckExact(v)) {
>                 if (p->version > 1) {
>                         unsigned char buf[8];
>                         if (_PyFloat_Pack8(PyComplex_RealAsDouble(v),
> @@ -236,7 +236,7 @@
>                 }
>         }
>  #endif
> -       else if (PyString_Check(v)) {
> +       else if (PyString_CheckExact(v)) {
>                 if (p->strings && PyString_CHECK_INTERNED(v)) {
>                         PyObject *o = PyDict_GetItem(p->strings, v);
>                         if (o) {
> @@ -273,7 +273,7 @@
>                 w_string(PyString_AS_STRING(v), (int)n, p);
>         }
>  #ifdef Py_USING_UNICODE
> -       else if (PyUnicode_Check(v)) {
> +       else if (PyUnicode_CheckExact(v)) {
>                 PyObject *utf8;
>                 utf8 = PyUnicode_AsUTF8String(v);
>                 if (utf8 == NULL) {
> @@ -293,7 +293,7 @@
>                 Py_DECREF(utf8);
>         }
>  #endif
> -       else if (PyTuple_Check(v)) {
> +       else if (PyTuple_CheckExact(v)) {
>                 w_byte(TYPE_TUPLE, p);
>                 n = PyTuple_Size(v);
>                 w_long((long)n, p);
> @@ -301,7 +301,7 @@
>                         w_object(PyTuple_GET_ITEM(v, i), p);
>                 }
>         }
> -       else if (PyList_Check(v)) {
> +       else if (PyList_CheckExact(v)) {
>                 w_byte(TYPE_LIST, p);
>                 n = PyList_GET_SIZE(v);
>                 w_long((long)n, p);
> @@ -309,7 +309,7 @@
>                         w_object(PyList_GET_ITEM(v, i), p);
>                 }
>         }
> -       else if (PyDict_Check(v)) {
> +       else if (PyDict_CheckExact(v)) {
>                 Py_ssize_t pos;
>                 PyObject *key, *value;
>                 w_byte(TYPE_DICT, p);
> @@ -321,7 +321,7 @@
>                 }
>                 w_object((PyObject *)NULL, p);
>         }
> -       else if (PyAnySet_Check(v)) {
> +       else if (PyAnySet_CheckExact(v)) {
>                 PyObject *value, *it;
>
>                 if (PyObject_TypeCheck(v, &PySet_Type))
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-- 
--Guido van Rossum (home page: http://www.python.org/~guido/)


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