diff -r a56cd7aeac5e Lib/test/test_exceptions.py
--- a/Lib/test/test_exceptions.py	Tue Mar 22 09:06:38 2011 -0700
+++ b/Lib/test/test_exceptions.py	Tue Mar 22 23:26:32 2011 +0100
@@ -464,6 +464,15 @@
 self.assertTrue(e is RuntimeError, e)
 self.assertIn("maximum recursion depth exceeded", str(v))
 
+ def test_new_returns_invalid_instance(self):
+ # See issue #11627.
+ class MyException(Exception):
+ def __new__(cls, *args):
+ return object()
+
+ with self.assertRaises(TypeError):
+ raise MyException
+
 
 
 # Helper class used by TestSameStrAndUnicodeMsg
diff -r a56cd7aeac5e Python/ceval.c
--- a/Python/ceval.c	Tue Mar 22 09:06:38 2011 -0700
+++ b/Python/ceval.c	Tue Mar 22 23:26:32 2011 +0100
@@ -3515,9 +3515,17 @@
 Py_DECREF(tmp);
 }
 
- if (PyExceptionClass_Check(type))
+ if (PyExceptionClass_Check(type)) {
 PyErr_NormalizeException(&type, &value, &tb);
-
+ if (!PyExceptionInstance_Check(value)) {
+ PyErr_Format(PyExc_TypeError,
+ "calling %s() should have returned an instance of "
+ "BaseException, not '%s'",
+ ((PyTypeObject *)type)->tp_name,
+ Py_TYPE(value)->tp_name);
+ goto raise_error;
+ }
+ }
 else if (PyExceptionInstance_Check(type)) {
 /* Raising an instance. The value should be a dummy. */
 if (value != Py_None) {
</div><div class="naked_ctrl">
<form action="/index.cgi/contrast" method="get" name="gate">
<p><a href="http://altstyle.alfasado.net">AltStyle</a> によって変換されたページ <a href="https://bugs.python.org/file21347/issue11627_py27.patch">(-&gt;オリジナル)</a>
/ <label>アドレス: <input type="text" name="naked_post_url" value="https://bugs.python.org/file21347/issue11627_py27.patch" size="22" /></label> <label>モード: <select name="naked_post_mode">
<option value="default">デフォルト</option>
<option value="speech">音声ブラウザ</option>
<option value="ruby">ルビ付き</option>
<option value="contrast" selected="selected">配色反転</option>
<option value="larger-text">文字拡大</option>
<option value="mobile">モバイル</option>
</select>
<input type="submit" value="表示" />
</p>
</form>
</div>