diff --git a/Lib/test/test_dictviews.py b/Lib/test/test_dictviews.py index b585bdd90203ea..1edeec55d07791 100644 --- a/Lib/test/test_dictviews.py +++ b/Lib/test/test_dictviews.py @@ -1,5 +1,6 @@ import copy import pickle +import sys import unittest import collections from test import test_support @@ -169,6 +170,20 @@ def test_items_set_operations(self): def test_recursive_repr(self): d = {} d[42] = d.viewvalues() + r = repr(d) + # Cannot perform a stronger test, as the contents of the repr + # are implementation-dependent. All we can say is that we + # want a str result, not an exception of any sort. + self.assertIsInstance(r, str) + d[42] = d.viewitems() + r = repr(d) + # Again. + self.assertIsInstance(r, str) + + def test_deeply_nested_repr(self): + d = {} + for i in range(sys.getrecursionlimit() + 100): + d = {42: d.viewvalues()} self.assertRaises(RuntimeError, repr, d) def test_abc_registry(self): diff --git a/Lib/test/test_ordered_dict.py b/Lib/test/test_ordered_dict.py index 85e4841fbb4b21..17326c5190c61e 100644 --- a/Lib/test/test_ordered_dict.py +++ b/Lib/test/test_ordered_dict.py @@ -220,6 +220,19 @@ def test_repr_recursive(self): self.assertEqual(repr(od), "OrderedDict([('a', None), ('b', None), ('c', None), ('x', ...)])") + def test_repr_recursive_values(self): + od = OrderedDict() + od[42] = od.viewvalues() + r = repr(od) + # Cannot perform a stronger test, as the contents of the repr + # are implementation-dependent. All we can say is that we + # want a str result, not an exception of any sort. + self.assertIsInstance(r, str) + od[42] = od.viewitems() + r = repr(od) + # Again. + self.assertIsInstance(r, str) + def test_setdefault(self): pairs = [('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)] shuffle(pairs) diff --git a/Misc/NEWS.d/next/Core and Builtins/2017-12-13-16-46-23.bpo-18533.Dlk8d7.rst b/Misc/NEWS.d/next/Core and Builtins/2017-12-13-16-46-23.bpo-18533.Dlk8d7.rst new file mode 100644 index 00000000000000..2ffd5718d6ac5e --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2017-12-13-16-46-23.bpo-18533.Dlk8d7.rst @@ -0,0 +1,3 @@ +``repr()`` on a dict containing its own ``viewvalues()`` or +``viewitems()`` no longer raises ``RuntimeError``. Instead, use +``...``, as for other recursive structures. Patch by Ben North. diff --git a/Objects/dictobject.c b/Objects/dictobject.c index a792b2dfa21074..c544ecd8c2d254 100644 --- a/Objects/dictobject.c +++ b/Objects/dictobject.c @@ -3005,21 +3005,29 @@ dictview_repr(dictviewobject *dv) { PyObject *seq; PyObject *seq_str; - PyObject *result; + PyObject *result = NULL; + Py_ssize_t rc; + rc = Py_ReprEnter((PyObject *)dv); + if (rc != 0) { + return rc > 0 ? PyString_FromString("...") : NULL; + } seq = PySequence_List((PyObject *)dv); - if (seq == NULL) - return NULL; - + if (seq == NULL) { + goto Done; + } seq_str = PyObject_Repr(seq); + Py_DECREF(seq); + if (seq_str == NULL) { - Py_DECREF(seq); - return NULL; + goto Done; } result = PyString_FromFormat("%s(%s)", Py_TYPE(dv)->tp_name, PyString_AS_STRING(seq_str)); Py_DECREF(seq_str); - Py_DECREF(seq); + +Done: + Py_ReprLeave((PyObject *)dv); return result; }