From b4a76e3fe8499cb3a1145f3aaab0a6fb2e7c9246 Mon Sep 17 00:00:00 2001
From: Victor Stinner <haypo@maggie.(none)>
Date: Tue, 15 Jun 2010 00:06:11 +0200
Subject: [PATCH] Issue #8991: convertbuffer() rejects discontigious buffers.

---
 Misc/NEWS        |    2 ++
 Python/getargs.c |   34 +++++++++++-----------------------
 2 files changed, 13 insertions(+), 23 deletions(-)

diff --git a/Misc/NEWS b/Misc/NEWS
index 6855696..9e24399 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,8 @@ What's New in Python 3.2 Alpha 1?
 Core and Builtins
 -----------------
 
+- Issue #8991: convertbuffer() rejects discontigious buffers.
+
 - Issue #8592: PyArg_Parse*() functions raise a TypeError for "y", "u" and "Z"
   formats if the string contains a null byte/character. Write unit tests for
   string formats.
diff --git a/Python/getargs.c b/Python/getargs.c
index 20f4814..8171377 100644
--- a/Python/getargs.c
+++ b/Python/getargs.c
@@ -863,7 +863,8 @@ convertsimple(PyObject *arg, const char **p_format, va_list *p_va, int flags,
                     return converterr(CONV_UNICODE,
                                       arg, msgbuf, bufsize);
                 PyBuffer_FillInfo(p, arg,
-                                  PyBytes_AS_STRING(uarg), PyBytes_GET_SIZE(uarg),
+                                  PyBytes_AS_STRING(uarg),
+                                  PyBytes_GET_SIZE(uarg),
                                   1, 0);
             }
             else { /* any buffer-like object */
@@ -1328,13 +1329,15 @@ convertsimple(PyObject *arg, const char **p_format, va_list *p_va, int flags,
                 PyErr_Clear();
                 return converterr("read-write buffer", arg, msgbuf, bufsize);
             }
+            if (!PyBuffer_IsContiguous((Py_buffer*)p, 'C')) {
+                PyBuffer_Release((Py_buffer*)p);
+                return converterr("contiguous buffer", arg, msgbuf, bufsize);
+            }
             if (addcleanup(p, freelist, cleanup_buffer)) {
                 return converterr(
                     "(cleanup problem)",
                     arg, msgbuf, bufsize);
             }
-            if (!PyBuffer_IsContiguous((Py_buffer*)p, 'C'))
-                return converterr("contiguous buffer", arg, msgbuf, bufsize);
             break;
         }
 
@@ -1380,42 +1383,27 @@ convertbuffer(PyObject *arg, void **p, char **errmsg)
 
     *errmsg = NULL;
     *p = NULL;
-    if (pb == NULL ||
-        pb->bf_getbuffer == NULL ||
-        pb->bf_releasebuffer != NULL) {
-        *errmsg = "bytes or read-only buffer";
+    if (pb != NULL && pb->bf_releasebuffer != NULL) {
+        *errmsg = "read-only pinned buffer";
         return -1;
     }
-
-    if (PyObject_GetBuffer(arg, &view, PyBUF_SIMPLE) != 0) {
-        *errmsg = "bytes or single-segment read-only buffer";
+    if (getbuffer(arg, &view, errmsg) < 0)
         return -1;
-    }
     count = view.len;
     *p = view.buf;
     PyBuffer_Release(&view);
     return count;
 }
 
-/* XXX for 3.x, getbuffer and convertbuffer can probably
-   be merged again. */
 static int
 getbuffer(PyObject *arg, Py_buffer *view, char **errmsg)
 {
-    PyBufferProcs *pb = Py_TYPE(arg)->tp_as_buffer;
-    if (pb == NULL) {
+    if (PyObject_GetBuffer(arg, view, PyBUF_SIMPLE) != 0) {
         *errmsg = "bytes or buffer";
         return -1;
     }
-    if (pb->bf_getbuffer == NULL) {
-        *errmsg = "convertible to a buffer";
-        return -1;
-    }
-    if (PyObject_GetBuffer(arg, view, 0) < 0) {
-        *errmsg = "convertible to a buffer";
-        return -1;
-    }
     if (!PyBuffer_IsContiguous(view, 'C')) {
+        PyBuffer_Release(&view);
         *errmsg = "contiguous buffer";
         return -1;
     }
-- 
1.6.2.5