bpo-32137: The repr of deeply nested dict now raises a RecursionError (#4570)
instead of crashing due to a stack overflow.
This perhaps will fix similar problems in other extension types.
diff --git a/Lib/test/list_tests.py b/Lib/test/list_tests.py
index ce9db9a..ed63fda 100644
--- a/Lib/test/list_tests.py
+++ b/Lib/test/list_tests.py
@@ -53,10 +53,11 @@
self.assertEqual(str(a2), "[0, 1, 2, [...], 3]")
self.assertEqual(repr(a2), "[0, 1, 2, [...], 3]")
- l0 = []
+ def test_repr_deep(self):
+ a = self.type2test([])
for i in range(sys.getrecursionlimit() + 100):
- l0 = [l0]
- self.assertRaises(RecursionError, repr, l0)
+ a = self.type2test([a])
+ self.assertRaises(RecursionError, repr, a)
def test_print(self):
d = self.type2test(range(200))
diff --git a/Lib/test/mapping_tests.py b/Lib/test/mapping_tests.py
index ff82f4e..53f29f6 100644
--- a/Lib/test/mapping_tests.py
+++ b/Lib/test/mapping_tests.py
@@ -1,6 +1,7 @@
# tests common to dict and UserDict
import unittest
import collections
+import sys
class BasicTestMappingProtocol(unittest.TestCase):
@@ -619,6 +620,14 @@
d = self._full_mapping({1: BadRepr()})
self.assertRaises(Exc, repr, d)
+ def test_repr_deep(self):
+ d = self._empty_mapping()
+ for i in range(sys.getrecursionlimit() + 100):
+ d0 = d
+ d = self._empty_mapping()
+ d[1] = d0
+ self.assertRaises(RecursionError, repr, d)
+
def test_eq(self):
self.assertEqual(self._empty_mapping(), self._empty_mapping())
self.assertEqual(self._full_mapping({1: 2}),
diff --git a/Lib/test/test_dict.py b/Lib/test/test_dict.py
index 8013f37..4386eda 100644
--- a/Lib/test/test_dict.py
+++ b/Lib/test/test_dict.py
@@ -468,6 +468,12 @@
d = {1: BadRepr()}
self.assertRaises(Exc, repr, d)
+ def test_repr_deep(self):
+ d = {}
+ for i in range(sys.getrecursionlimit() + 100):
+ d = {1: d}
+ self.assertRaises(RecursionError, repr, d)
+
def test_eq(self):
self.assertEqual({}, {})
self.assertEqual({1: 2}, {1: 2})
diff --git a/Misc/NEWS.d/next/Core and Builtins/2017-11-26-14-36-30.bpo-32137.Stj5nL.rst b/Misc/NEWS.d/next/Core and Builtins/2017-11-26-14-36-30.bpo-32137.Stj5nL.rst
new file mode 100644
index 0000000..f8f4ab9
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2017-11-26-14-36-30.bpo-32137.Stj5nL.rst
@@ -0,0 +1,2 @@
+The repr of deeply nested dict now raises a RecursionError instead of
+crashing due to a stack overflow.
diff --git a/Objects/listobject.c b/Objects/listobject.c
index 8576b7a..8794e37 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -364,10 +364,7 @@
goto error;
}
- if (Py_EnterRecursiveCall(" while getting the repr of a list"))
- goto error;
s = PyObject_Repr(v->ob_item[i]);
- Py_LeaveRecursiveCall();
if (s == NULL)
goto error;
diff --git a/Objects/object.c b/Objects/object.c
index 674180d..a0d651d 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -463,7 +463,12 @@
assert(!PyErr_Occurred());
#endif
+ /* It is possible for a type to have a tp_repr representation that loops
+ infinitely. */
+ if (Py_EnterRecursiveCall(" while getting the repr of an object"))
+ return NULL;
res = (*v->ob_type->tp_repr)(v);
+ Py_LeaveRecursiveCall();
if (res == NULL)
return NULL;
if (!PyUnicode_Check(res)) {
diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c
index 964db3b..3a60946 100644
--- a/Objects/tupleobject.c
+++ b/Objects/tupleobject.c
@@ -303,10 +303,7 @@
goto error;
}
- if (Py_EnterRecursiveCall(" while getting the repr of a tuple"))
- goto error;
s = PyObject_Repr(v->ob_item[i]);
- Py_LeaveRecursiveCall();
if (s == NULL)
goto error;