#3305: self->stream can be NULL.

2 files changed, 11 insertions, 2 deletions

diff --git a/Lib/test/test_multibytecodec.py b/Lib/test/test_multibytecodec.py
index f2b042cc7c..090374cdaf 100644
--- a/Lib/test/test_multibytecodec.py
+++ b/Lib/test/test_multibytecodec.py
@@ -8,6 +8,7 @@ from test import test_support
 from test import test_multibytecodec_support
 from test.test_support import TESTFN
 import unittest, StringIO, codecs, sys, os
+import _multibytecodec
 
 ALL_CJKENCODINGS = [
 # _codecs_cn
@@ -53,6 +54,14 @@ class Test_MultibyteCodec(unittest.TestCase):
         finally:
             os.unlink(TESTFN)
 
+    def test_init_segfault(self):
+        # bug #3305: this used to segfault
+        self.assertRaises(AttributeError,
+                          _multibytecodec.MultibyteStreamReader, None)
+        self.assertRaises(AttributeError,
+                          _multibytecodec.MultibyteStreamWriter, None)
+
+
 class Test_IncrementalEncoder(unittest.TestCase):
 
     def test_stateless(self):
diff --git a/Modules/cjkcodecs/multibytecodec.c b/Modules/cjkcodecs/multibytecodec.c
index a1b0ca9180..2bd8b0dcce 100644
--- a/Modules/cjkcodecs/multibytecodec.c
+++ b/Modules/cjkcodecs/multibytecodec.c
@@ -1484,7 +1484,7 @@ mbstreamreader_dealloc(MultibyteStreamReaderObject *self)
 {
 	PyObject_GC_UnTrack(self);
 	ERROR_DECREF(self->errors);
-	Py_DECREF(self->stream);
+	Py_XDECREF(self->stream);
 	Py_TYPE(self)->tp_free(self);
 }
 
@@ -1686,7 +1686,7 @@ mbstreamwriter_dealloc(MultibyteStreamWriterObject *self)
 {
 	PyObject_GC_UnTrack(self);
 	ERROR_DECREF(self->errors);
-	Py_DECREF(self->stream);
+	Py_XDECREF(self->stream);
 	Py_TYPE(self)->tp_free(self);
 }