From 5a1ca6e36802f48a6cbcbd563770427ded747e0f Mon Sep 17 00:00:00 2001
From: Benjamin Peterson <benjamin@python.org>
Date: Sat, 20 Nov 2010 17:26:25 +0000
Subject: [PATCH] Merged revisions 86587 via svnmerge from
 svn+ssh://pythondev@svn.python.org/python/branches/py3k

........
  r86587 | benjamin.peterson | 2010-11-20 11:24:04 -0600 (Sat, 20 Nov 2010) | 1 line

  correct logic when pos is after the string #10467
........
---
 Lib/test/test_memoryio.py |  5 +++++
 Misc/NEWS                 |  5 +++++
 Modules/_io/bytesio.c     | 11 ++++++++---
 3 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/Lib/test/test_memoryio.py b/Lib/test/test_memoryio.py
index 89c8196676d..027ac9452d0 100644
--- a/Lib/test/test_memoryio.py
+++ b/Lib/test/test_memoryio.py
@@ -392,6 +392,11 @@ class PyBytesIOTest(MemoryTestMixin, MemorySeekTestMixin, unittest.TestCase):
         self.assertEqual(a.tostring(), b"1234567890d")
         memio.close()
         self.assertRaises(ValueError, memio.readinto, b)
+        memio = self.ioclass(b"123")
+        b = bytearray()
+        memio.seek(42)
+        memio.readinto(b)
+        self.assertEqual(b, b"")
 
     def test_relative_seek(self):
         buf = self.buftype("1234567890")
diff --git a/Misc/NEWS b/Misc/NEWS
index b51e6e67b11..7794521353a 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -19,6 +19,11 @@ Library
 - Issue #10198: fix duplicate header written to wave files when writeframes()
   is called without data.
 
+- Issue #10467: Fix BytesIO.readinto() after seeking into a position after the
+  end of the file.
+
+- Issue #1682942: configparser supports alternative option/value delimiters.
+
 Build
 -----
 
diff --git a/Modules/_io/bytesio.c b/Modules/_io/bytesio.c
index 29fb1ead018..c8fb3eb95f4 100644
--- a/Modules/_io/bytesio.c
+++ b/Modules/_io/bytesio.c
@@ -391,15 +391,20 @@ static PyObject *
 bytesio_readinto(bytesio *self, PyObject *buffer)
 {
     void *raw_buffer;
-    Py_ssize_t len;
+    Py_ssize_t len, n;
 
     CHECK_CLOSED(self);
 
     if (PyObject_AsWriteBuffer(buffer, &raw_buffer, &len) == -1)
         return NULL;
 
-    if (self->pos + len > self->string_size)
-        len = self->string_size - self->pos;
+    /* adjust invalid sizes */
+    n = self->string_size - self->pos;
+    if (len > n) {
+        len = n;
+        if (len < 0)
+            len = 0;
+    }
 
     memcpy(raw_buffer, self->buf + self->pos, len);
     assert(self->pos + len < PY_SSIZE_T_MAX);