#2355: py3k warning for buffer().

Lib/test/test_py3kwarn.py

@@ -118,6 +118,11 @@ class TestPy3KWarnings(unittest.TestCase):
             with catch_warning() as w:
                 self.assertWarning(set(), w, expected)
 
+    def test_buffer(self):
+        expected = 'buffer will be removed in 3.x'
+        with catch_warning() as w:
+            self.assertWarning(buffer('a'), w, expected)
+
 
 def test_main():
     run_unittest(TestPy3KWarnings)

Misc/NEWS

@@ -11,7 +11,9 @@ What's New in Python 2.6 alpha 2?
 
 Core and builtins
 -----------------
- 
+
+- Issue #2355: add Py3k warning for buffer().
+
 - Issue #1477: With narrow Unicode builds, the unicode escape sequence
   \Uxxxxxxxx did not accept values outside the Basic Multilingual Plane.  This
   affected raw unicode literals and the 'raw-unicode-escape' codec.  Now

Objects/bufferobject.c

@@ -229,6 +229,11 @@ PyBuffer_New(Py_ssize_t size)
 static PyObject *
 buffer_new(PyTypeObject *type, PyObject *args, PyObject *kw)
 {
+	if (Py_Py3kWarningFlag &&
+	    PyErr_WarnEx(PyExc_DeprecationWarning,
+	    "buffer will be removed in 3.x", 1) < 0)
+		return NULL;
+	
 	PyObject *ob;
 	Py_ssize_t offset = 0;
 	Py_ssize_t size = Py_END_OF_BUFFER;