diff -r 9770d5114890 -r 666c3f440c4b Lib/test/test_socket.py
--- a/Lib/test/test_socket.py	Thu Jan 13 03:52:26 2011 +0100
+++ b/Lib/test/test_socket.py	Thu Jan 13 11:23:45 2011 +0200
@@ -441,6 +441,45 @@
         # Check that setting it to an invalid type raises TypeError
         self.assertRaises(TypeError, socket.setdefaulttimeout, "spam")
 
+    def test_7322(self):
+        # Test issue 7322: Don't lose data after calling readline()
+        # on a socket with a timeout
+        self._test_7322("rb", 0, b"XXXYYYZZZ", b"XXXYYYZZZ", b"a", b"a")
+        self._test_7322("rb", 5, b"XXXYYYZZZ", b"XXXYYYZZZ", b"a", b"a")
+        self._test_7322("rb", 10, b"XXXYYYZZZ", b"XXXYYYZZZ", b"a", b"a")
+        self._test_7322("r", 5, b"XXXYYYZZZ", "XXXYYYZZZ", b"a", "a")
+        self._test_7322("r", 10, b"XXXYYYZZZ", "XXXYYYZZZ", b"a", "a")
+        self._test_7322("rb", 0, b"", b"", b"a", b"a")
+        self._test_7322("rb", 5, b"", b"", b"a", b"a")
+        self._test_7322("r", 5, b"", "", b"a", "a")
+
+    def _test_7322_setup(self):
+        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
+            c = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+            s.bind(('', 0))
+            s.listen(5)
+            c.connect(('localhost', s.getsockname()[1]))
+            c.settimeout(1)
+            return (c, s.accept()[0])
+
+    def _test_7322(self, mode, bufsize, s1, s2, s3, s4):
+        c, s = self._test_7322_setup()
+        try:
+            f = c.makefile(mode, buffering=bufsize)
+            s.send(s1)
+
+            try:
+                print(f.readline())
+            except socket.timeout as e:
+                assert(e.data == s2)
+
+            s.send(s3)
+            assert(f.read(1) == s4)
+        finally:
+            f.close()
+            c.close()
+            s.close()
+
     def testIPv4_inet_aton_fourbytes(self):
         if not hasattr(socket, 'inet_aton'):
             return  # No inet_aton, nothing to check
diff -r 9770d5114890 -r 666c3f440c4b Modules/_io/bufferedio.c
--- a/Modules/_io/bufferedio.c	Thu Jan 13 03:52:26 2011 +0100
+++ b/Modules/_io/bufferedio.c	Thu Jan 13 11:23:45 2011 +0200
@@ -902,6 +902,7 @@
 static PyObject *
 _buffered_readline(buffered *self, Py_ssize_t limit)
 {
+    PyObject *ptype, *pvalue, *ptraceback;
     PyObject *res = NULL;
     PyObject *chunks = NULL;
     Py_ssize_t n, written = 0;
@@ -1005,6 +1006,15 @@
 end:
     LEAVE_BUFFERED(self)
 end_unlocked:
+    if (res == NULL && chunks != NULL) {
+        res = _PyBytes_Join(_PyIO_empty_bytes, chunks);
+        PyErr_Fetch(&ptype, &pvalue, &ptraceback);
+        PyObject_SetAttrString(pvalue, "data", res);
+        PyErr_Restore(ptype, pvalue, ptraceback);
+        Py_DECREF(res);
+        Py_DECREF(chunks);
+        return NULL;
+    }
     Py_XDECREF(chunks);
     return res;
 }
diff -r 9770d5114890 -r 666c3f440c4b Modules/_io/iobase.c
--- a/Modules/_io/iobase.c	Thu Jan 13 03:52:26 2011 +0100
+++ b/Modules/_io/iobase.c	Thu Jan 13 11:23:45 2011 +0200
@@ -446,6 +446,7 @@
 iobase_readline(PyObject *self, PyObject *args)
 {
     /* For backwards compatibility, a (slowish) readline(). */
+    PyObject *ptype, *pvalue, *ptraceback;
 
     Py_ssize_t limit = -1;
     int has_peek = 0;
@@ -533,6 +534,12 @@
     Py_DECREF(buffer);
     return result;
   fail:
+    result = PyBytes_FromStringAndSize(PyByteArray_AS_STRING(buffer),
+                                       PyByteArray_GET_SIZE(buffer));
+    PyErr_Fetch(&ptype, &pvalue, &ptraceback);
+    PyObject_SetAttrString(pvalue, "data", result);
+    PyErr_Restore(ptype, pvalue, ptraceback);
+    Py_DECREF(result);
     Py_DECREF(buffer);
     return NULL;
 }
diff -r 9770d5114890 -r 666c3f440c4b Modules/_io/textio.c
--- a/Modules/_io/textio.c	Thu Jan 13 03:52:26 2011 +0100
+++ b/Modules/_io/textio.c	Thu Jan 13 11:23:45 2011 +0200
@@ -1672,6 +1672,7 @@
 static PyObject *
 _textiowrapper_readline(textio *self, Py_ssize_t limit)
 {
+    PyObject *ptype, *pvalue, *ptraceback;
     PyObject *line = NULL, *chunks = NULL, *remaining = NULL;
     Py_ssize_t start, endpos, chunked, offset_to_buffer;
     int res;
@@ -1817,6 +1818,18 @@
     return line;
 
   error:
+    Py_XDECREF(line);
+    line = PyUnicode_Join(_PyIO_empty_str, chunks);
+    if (line == NULL)
+        line = PyUnicode_FromStringAndSize(NULL, 0);
+    if (remaining != NULL) {
+        PyObject *result = PyUnicode_Concat(line, remaining);
+        Py_XDECREF(line);
+        line = result;
+    }
+    PyErr_Fetch(&ptype, &pvalue, &ptraceback);
+    PyObject_SetAttrString(pvalue, "data", line);
+    PyErr_Restore(ptype, pvalue, ptraceback);
     Py_XDECREF(chunks);
     Py_XDECREF(remaining);
     Py_XDECREF(line);