[Python-checkins] cpython (3.4): Issue #23370: Fix off-by-one error for non-contiguous buffers.

Sun Feb 1 19:21:07 CET 2015

https://hg.python.org/cpython/rev/4d95956a748e
changeset: 94429:4d95956a748e
branch: 3.4
parent: 94425:35fa000406c4
user: Stefan Krah <skrah at bytereef.org>
date: Sun Feb 01 16:19:23 2015 +0100
summary:
 Issue #23370: Fix off-by-one error for non-contiguous buffers.
files:
 Modules/_testcapimodule.c | 51 +++++++++++++++++++++++++++
 Objects/abstract.c | 4 +-
 2 files changed, 53 insertions(+), 2 deletions(-)

diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -2467,6 +2467,56 @@
 return NULL;
 return PyMemoryView_FromBuffer(&info);
 }
+ 
+static PyObject *
+test_from_contiguous(PyObject* self, PyObject *noargs)
+{
+ int data[9] = {-1,-1,-1,-1,-1,-1,-1,-1,-1};
+ int init[5] = {0, 1, 2, 3, 4};
+ Py_ssize_t itemsize = sizeof(int);
+ Py_ssize_t shape = 5;
+ Py_ssize_t strides = 2 * itemsize;
+ Py_buffer view = {
+ data,
+ NULL,
+ 5 * itemsize,
+ itemsize,
+ 1,
+ 1,
+ NULL,
+ &shape,
+ &strides,
+ NULL,
+ NULL
+ };
+ int *ptr;
+ int i;
+
+ PyBuffer_FromContiguous(&view, init, view.len, 'C');
+ ptr = view.buf;
+ for (i = 0; i < 5; i++) {
+ if (ptr[2*i] != i) {
+ PyErr_SetString(TestError,
+ "test_from_contiguous: incorrect result");
+ return NULL;
+ }
+ }
+
+ view.buf = &data[8];
+ view.strides[0] = -2 * itemsize;
+
+ PyBuffer_FromContiguous(&view, init, view.len, 'C');
+ ptr = view.buf;
+ for (i = 0; i < 5; i++) {
+ if (*(ptr-2*i) != i) {
+ PyErr_SetString(TestError,
+ "test_from_contiguous: incorrect result");
+ return NULL;
+ }
+ }
+
+ Py_RETURN_NONE;
+}
 
 /* Test that the fatal error from not having a current thread doesn't
 cause an infinite loop. Run via Lib/test/test_capi.py */
@@ -3031,6 +3081,7 @@
 {"test_string_to_double", (PyCFunction)test_string_to_double, METH_NOARGS},
 {"test_unicode_compare_with_ascii", (PyCFunction)test_unicode_compare_with_ascii, METH_NOARGS},
 {"test_capsule", (PyCFunction)test_capsule, METH_NOARGS},
+ {"test_from_contiguous", (PyCFunction)test_from_contiguous, METH_NOARGS},
 {"getargs_tuple", getargs_tuple, METH_VARARGS},
 {"getargs_keywords", (PyCFunction)getargs_keywords,
 METH_VARARGS|METH_KEYWORDS},
diff --git a/Objects/abstract.c b/Objects/abstract.c
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -488,7 +488,7 @@
 
 /* Otherwise a more elaborate scheme is needed */
 
- /* XXX(nnorwitz): need to check for overflow! */
+ /* view->ndim <= 64 */
 indices = (Py_ssize_t *)PyMem_Malloc(sizeof(Py_ssize_t)*(view->ndim));
 if (indices == NULL) {
 PyErr_NoMemory();
@@ -510,10 +510,10 @@
 */
 elements = len / view->itemsize;
 while (elements--) {
- addone(view->ndim, indices, view->shape);
 ptr = PyBuffer_GetPointer(view, indices);
 memcpy(ptr, src, view->itemsize);
 src += view->itemsize;
+ addone(view->ndim, indices, view->shape);
 }
 
 PyMem_Free(indices);
-- 
Repository URL: https://hg.python.org/cpython
