From 49281076c1dcc3d8d7b5592a49dd9c65c1e6b8a4 Mon Sep 17 00:00:00 2001
From: Brian Curtin <brian@python.org>
Date: Thu, 11 Aug 2011 09:41:31 -0500
Subject: [PATCH 1/2] Add doc for Py_RETURN_NOTIMPLEMENTED, added in #12724.

---
 Doc/c-api/object.rst | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/Doc/c-api/object.rst b/Doc/c-api/object.rst
index d0d45ad0012..88ba5ac0c4e 100644
--- a/Doc/c-api/object.rst
+++ b/Doc/c-api/object.rst
@@ -6,6 +6,19 @@ Object Protocol
 ===============
 
 
+.. c:var:: PyObject* Py_NotImplemented
+
+   The ``NotImplemented`` singleton, used to signal that an operation is
+   not implemented for the given type combination.
+
+
+.. c:macro:: Py_RETURN_NOTIMPLEMENTED
+
+   Properly handle returning :c:data:`Py_NotImplemented` from within a C
+   function (that is, increment the reference count of NotImplemented and
+   return it).
+
+
 .. c:function:: int PyObject_Print(PyObject *o, FILE *fp, int flags)
 
    Print an object *o*, on file *fp*.  Returns ``-1`` on error.  The flags argument

From f6c7a8595ea77a2a470309127752432df2f6e872 Mon Sep 17 00:00:00 2001
From: Antoine Pitrou <solipsis@pitrou.net>
Date: Thu, 11 Aug 2011 21:04:02 +0200
Subject: [PATCH 2/2] Issue #12687: Fix a possible buffering bug when
 unpickling text mode (protocol 0, mostly) pickles.

---
 Lib/test/pickletester.py | 13 +++++++++++++
 Misc/NEWS                |  3 +++
 Modules/_pickle.c        |  3 +--
 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/Lib/test/pickletester.py b/Lib/test/pickletester.py
index a843486a42a..e4ab0ddf72f 100644
--- a/Lib/test/pickletester.py
+++ b/Lib/test/pickletester.py
@@ -1418,6 +1418,19 @@ class AbstractPicklerUnpicklerObjectTests(unittest.TestCase):
     def test_multiple_unpicklings_unseekable(self):
         self._check_multiple_unpicklings(UnseekableIO)
 
+    def test_unpickling_buffering_readline(self):
+        # Issue #12687: the unpickler's buffering logic could fail with
+        # text mode opcodes.
+        data = list(range(10))
+        for proto in protocols:
+            for buf_size in range(1, 11):
+                f = io.BufferedRandom(io.BytesIO(), buffer_size=buf_size)
+                pickler = self.pickler_class(f, protocol=proto)
+                pickler.dump(data)
+                f.seek(0)
+                unpickler = self.unpickler_class(f)
+                self.assertEqual(unpickler.load(), data)
+
 
 if __name__ == "__main__":
     # Print some stuff that can be used to rewrite DATA{0,1,2}
diff --git a/Misc/NEWS b/Misc/NEWS
index b8c5877ea58..c9a0522cfc7 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -41,6 +41,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #12687: Fix a possible buffering bug when unpickling text mode
+  (protocol 0, mostly) pickles.
+
 - Issue #10087: Fix the html output format of the calendar module.
 
 - Issue #12540: Prevent zombie IDLE processes on Windows due to changes
diff --git a/Modules/_pickle.c b/Modules/_pickle.c
index 287f0a3c15a..001360b8610 100644
--- a/Modules/_pickle.c
+++ b/Modules/_pickle.c
@@ -1034,9 +1034,8 @@ _Unpickler_Readline(UnpicklerObject *self, char **result)
         num_read = _Unpickler_ReadFromFile(self, READ_WHOLE_LINE);
         if (num_read < 0)
             return -1;
-        *result = self->input_buffer;
         self->next_read_idx = num_read;
-        return num_read;
+        return _Unpickler_CopyLine(self, self->input_buffer, num_read, result);
     }
  
     /* If we get here, we've run off the end of the input string. Return the