From 0296a565205651b60a3a5690432beb6f3333a7fc Mon Sep 17 00:00:00 2001
From: Benjamin Peterson <benjamin@python.org>
Date: Fri, 13 Jan 2012 14:54:31 -0500
Subject: NULL and no exception set from tp_iternext means StopIteration

---
 Lib/test/test_pep380.py | 5 +++++
 Python/ceval.c          | 3 ++-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/Lib/test/test_pep380.py b/Lib/test/test_pep380.py
index 53e9735..6554b0f 100644
--- a/Lib/test/test_pep380.py
+++ b/Lib/test/test_pep380.py
@@ -831,6 +831,11 @@ class TestPEP380Operation(unittest.TestCase):
             "Enter f",
         ])
 
+    def test_yield_from_empty(self):
+        def g():
+            yield from ()
+        self.assertRaises(StopIteration, next, g())
+
 
 def test_main():
     from test import support
diff --git a/Python/ceval.c b/Python/ceval.c
index 134d1ee..98219b0 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -1839,7 +1839,8 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
             if (!retval) {
                 /* iter may be exhausted */
                 Py_CLEAR(x);
-                if (!PyErr_ExceptionMatches(PyExc_StopIteration)) {
+                if (PyErr_Occurred() &&
+                    !PyErr_ExceptionMatches(PyExc_StopIteration)) {
                     /* some other exception */
                     break;
                 }
-- 
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