diff -r 5b1a03a858e0 Python/errors.c
--- a/Python/errors.c	Wed Mar 25 01:20:30 2015 +0100
+++ b/Python/errors.c	Wed Mar 25 01:44:51 2015 +0100
@@ -52,8 +52,8 @@ PyErr_Restore(PyObject *type, PyObject *
     Py_XDECREF(oldtraceback);
 }
 
-void
-PyErr_SetObject(PyObject *exception, PyObject *value)
+static void
+_PyErr_SetObject(PyObject *exception, PyObject *value)
 {
     PyThreadState *tstate = PyThreadState_GET();
     PyObject *exc_value;
@@ -75,10 +75,6 @@ PyErr_SetObject(PyObject *exception, PyO
             /* We must normalize the value right now */
             PyObject *args, *fixed_value;
 
-            /* Issue #23571: PyEval_CallObject() must not be called with an
-               exception set */
-            PyErr_Clear();
-
             if (value == NULL || value == Py_None)
                 args = PyTuple_New(0);
             else if (PyTuple_Check(value)) {
@@ -120,6 +116,17 @@ PyErr_SetObject(PyObject *exception, PyO
     PyErr_Restore(exception, value, tb);
 }
 
+void
+PyErr_SetObject(PyObject *exception, PyObject *value)
+{
+    PyObject *etype, *val, *tb;
+    PyErr_Fetch(&etype, &val, &tb);
+    _PyErr_SetObject(exception, value);
+    if (etype != NULL)
+        _PyErr_ChainExceptions(etype, val, tb);
+}
+
+
 /* Set a key error with the specified argument, wrapping it in a
  * tuple automatically so that tuple keys are not unpacked as the
  * exception arguments. */
@@ -776,15 +783,17 @@ PyErr_BadInternalCall(void)
 PyObject *
 PyErr_FormatV(PyObject *exception, const char *format, va_list vargs)
 {
+    PyObject *etype, *val, *tb;
     PyObject* string;
 
-    /* Issue #23571: PyUnicode_FromFormatV() must not be called with an
-       exception set, it calls arbitrary Python code like PyObject_Repr() */
-    PyErr_Clear();
+    PyErr_Fetch(&etype, &val, &tb);
 
     string = PyUnicode_FromFormatV(format, vargs);
 
-    PyErr_SetObject(exception, string);
+    _PyErr_SetObject(exception, string);
+    if (etype != NULL)
+        _PyErr_ChainExceptions(etype, val, tb);
+
     Py_XDECREF(string);
     return NULL;
 }