commit a5af6e1af77ee0f9294c5776478a9c24d9fbab94
author Serhiy Storchaka <storchaka@gmail.com> Sun Mar 19 19:25:29 2017 +0200
committer GitHub <noreply@github.com> Sun Mar 19 19:25:29 2017 +0200
tree f4c9791260db737fea9da4f415d9facad9c96ae1
parent 77ed11552da3e01dd235b7d68988076866b1f604

bpo-25455: Fixed crashes in repr of recursive buffered file-like objects. (#514)

Modules/_io/bufferedio.c

diff --git a/Modules/_io/bufferedio.c b/Modules/_io/bufferedio.c
index 6c88bbb..59e9beb 100644
--- a/Modules/_io/bufferedio.c
+++ b/Modules/_io/bufferedio.c
@@ -1415,8 +1415,18 @@
         res = PyUnicode_FromFormat("<%s>", Py_TYPE(self)->tp_name);
     }
     else {
-        res = PyUnicode_FromFormat("<%s name=%R>",
-                                   Py_TYPE(self)->tp_name, nameobj);
+        int status = Py_ReprEnter((PyObject *)self);
+        res = NULL;
+        if (status == 0) {
+            res = PyUnicode_FromFormat("<%s name=%R>",
+                                       Py_TYPE(self)->tp_name, nameobj);
+            Py_ReprLeave((PyObject *)self);
+        }
+        else if (status > 0) {
+            PyErr_Format(PyExc_RuntimeError,
+                         "reentrant call inside %s.__repr__",
+                         Py_TYPE(self)->tp_name);
+        }
         Py_DECREF(nameobj);
     }
     return res;