Index: Objects/abstract.c
===================================================================
--- Objects/abstract.c	(révision 83197)
+++ Objects/abstract.c	(copie de travail)
@@ -267,6 +267,11 @@
                         "expected a single-segment buffer object");
         return -1;
     }
+    if (pb->bf_releasebuffer != NULL) {
+        PyErr_SetString(PyExc_TypeError,
+                        "expected a read-only buffer object");
+        return -1;
+    }
     len = (*pb->bf_getcharbuffer)(obj, 0, &pp);
     if (len < 0)
         return -1;
Index: Objects/bytearrayobject.c
===================================================================
--- Objects/bytearrayobject.c	(révision 83197)
+++ Objects/bytearrayobject.c	(copie de travail)
@@ -91,18 +91,6 @@
     return 1;
 }
 
-static Py_ssize_t
-bytearray_buffer_getcharbuf(PyByteArrayObject *self, Py_ssize_t index, const char **ptr)
-{
-    if ( index != 0 ) {
-        PyErr_SetString(PyExc_SystemError,
-                "accessing non-existent bytes segment");
-        return -1;
-    }
-    *ptr = PyByteArray_AS_STRING(self);
-    return Py_SIZE(self);
-}
-
 static int
 bytearray_getbuffer(PyByteArrayObject *obj, Py_buffer *view, int flags)
 {
@@ -2796,7 +2784,7 @@
     (readbufferproc)bytearray_buffer_getreadbuf,
     (writebufferproc)bytearray_buffer_getwritebuf,
     (segcountproc)bytearray_buffer_getsegcount,
-    (charbufferproc)bytearray_buffer_getcharbuf,
+    (charbufferproc)NULL,
     (getbufferproc)bytearray_getbuffer,
     (releasebufferproc)bytearray_releasebuffer,
 };
Index: Lib/test/test_io.py
===================================================================
--- Lib/test/test_io.py	(révision 83198)
+++ Lib/test/test_io.py	(copie de travail)
@@ -1507,9 +1507,9 @@
     def process_word(self):
         output = ''
         if self.buffer[0] == ord('i'):
-            self.i = min(99, int(self.buffer[1:] or 0)) # set input length
+            self.i = min(99, int(bytes(self.buffer[1:]) or 0)) # set input length
         elif self.buffer[0] == ord('o'):
-            self.o = min(99, int(self.buffer[1:] or 0)) # set output length
+            self.o = min(99, int(bytes(self.buffer[1:]) or 0)) # set output length
         else:
             output = self.buffer.decode('ascii')
             if len(output) < self.o:
Index: Lib/test/test_bytes.py
===================================================================
--- Lib/test/test_bytes.py	(révision 83197)
+++ Lib/test/test_bytes.py	(copie de travail)
@@ -787,7 +787,7 @@
         # Issue #7561: operations on empty bytearrays could crash in many
         # situations, due to a fragile implementation of the
         # PyByteArray_AS_STRING() C macro.
-        self.assertRaises(ValueError, int, bytearray(b''))
+        self.assertRaises(TypeError, int, bytearray(b''))
 
 
 class AssortedBytesTest(unittest.TestCase):