(Backport from r55770)

Bug #1728403: Fix a bug that CJKCodecs StreamReader hangs when it
reads a file that ends with incomplete sequence and sizehint argument
for .read() is specified.

diff --git a/Lib/test/test_multibytecodec.py b/Lib/test/test_multibytecodec.py
index a8666d31ccd05d1be06b145e51dd89f95234a154..dd933f34632b95097832116b9697e491c2dcf577 100644 (file)
--- a/Lib/test/test_multibytecodec.py
+++ b/Lib/test/test_multibytecodec.py
@@ -136,6 +136,14 @@ class Test_IncrementalDecoder(unittest.TestCase):
         self.assertRaises(UnicodeDecodeError, decoder.decode, '', True)
         self.assertEqual(decoder.decode('B@$'), u'\u4e16')
 
+class Test_StreamReader(unittest.TestCase):
+    def test_bug1728403(self):
+        try:
+            open(TESTFN, 'w').write('\xa1')
+            f = codecs.open(TESTFN, encoding='cp949')
+            self.assertRaises(UnicodeDecodeError, f.read, 2)
+        finally:
+            os.unlink(TESTFN)
 
 class Test_StreamWriter(unittest.TestCase):
     if len(u'\U00012345') == 2: # UCS2
@@ -223,6 +231,7 @@ def test_main():
     suite.addTest(unittest.makeSuite(Test_MultibyteCodec))
     suite.addTest(unittest.makeSuite(Test_IncrementalEncoder))
     suite.addTest(unittest.makeSuite(Test_IncrementalDecoder))
+    suite.addTest(unittest.makeSuite(Test_StreamReader))
     suite.addTest(unittest.makeSuite(Test_StreamWriter))
     suite.addTest(unittest.makeSuite(Test_ISO2022))
     test_support.run_suite(suite)

diff --git a/Misc/NEWS b/Misc/NEWS
index 10bf25c93db656e69fb8eb02030e3611b0e7ba4d..f4be238c606844296b72d4f1983113e87fcca275 100644 (file)
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,10 @@ What's New in Python 2.5.2c1?
 Library
 -------
 
+- Bug #1728403: Fix a bug that CJKCodecs StreamReader hangs when it
+  reads a file that ends with incomplete sequence and sizehint argument
+  for .read() is specified.
+
 - Bug #1730389: Have time.strptime() match spaces in a format argument with
   ``\s+`` instead of ``\s*``.
 

diff --git a/Modules/cjkcodecs/multibytecodec.c b/Modules/cjkcodecs/multibytecodec.c
index 7c6b989355a5eff1e730e11337d53a898af160d7..9fb9570225edb36c02d8faa149fa30803b03e828 100644 (file)
--- a/Modules/cjkcodecs/multibytecodec.c
+++ b/Modules/cjkcodecs/multibytecodec.c
@@ -1214,6 +1214,8 @@ mbstreamreader_iread(MultibyteStreamReaderObject *self,
        cres = NULL;
 
        for (;;) {
+               int endoffile;
+
                if (sizehint < 0)
                        cres = PyObject_CallMethod(self->stream,
                                        (char *)method, NULL);
@@ -1230,6 +1232,8 @@ mbstreamreader_iread(MultibyteStreamReaderObject *self,
                        goto errorexit;
                }
 
+               endoffile = (PyString_GET_SIZE(cres) == 0);
+
                if (self->pendingsize > 0) {
                        PyObject *ctr;
                        char *ctrdata;
@@ -1257,7 +1261,7 @@ mbstreamreader_iread(MultibyteStreamReaderObject *self,
                                (MultibyteStatefulDecoderContext *)self, &buf))
                        goto errorexit;
 
-               if (rsize == 0 || sizehint < 0) { /* end of file */
+               if (endoffile || sizehint < 0) {
                        if (buf.inbuf < buf.inbuf_end &&
                            multibytecodec_decerror(self->codec, &self->state,
                                        &buf, self->errors, MBERR_TOOFEW))