[Python-checkins] cpython (2.7): 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/209776d49a9a
changeset: 94428:209776d49a9a
branch: 2.7
parent: 94424:7ee7d9fac852
user: Stefan Krah <skrah at bytereef.org>
date: Sun Feb 01 16:10:35 2015 +0100
summary:
 Issue #23370: Fix off-by-one error for non-contiguous buffers.
files:
 Modules/_testcapimodule.c | 53 +++++++++++++++++++++++++++
 Objects/abstract.c | 4 +-
 2 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -424,6 +424,58 @@
 Py_RETURN_NONE;
 }
 
+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,
+ {0, 0},
+ 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;
+}
+
+
 /* Tests of PyLong_{As, From}{Unsigned,}Long(), and (#ifdef HAVE_LONG_LONG)
 PyLong_{As, From}{Unsigned,}LongLong().
 
@@ -1833,6 +1885,7 @@
 {"test_lazy_hash_inheritance", (PyCFunction)test_lazy_hash_inheritance,METH_NOARGS},
 {"test_broken_memoryview", (PyCFunction)test_broken_memoryview,METH_NOARGS},
 {"test_to_contiguous", (PyCFunction)test_to_contiguous, METH_NOARGS},
+ {"test_from_contiguous", (PyCFunction)test_from_contiguous, METH_NOARGS},
 {"test_long_api", (PyCFunction)test_long_api, METH_NOARGS},
 {"test_long_and_overflow", (PyCFunction)test_long_and_overflow,
 METH_NOARGS},
diff --git a/Objects/abstract.c b/Objects/abstract.c
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -550,7 +550,7 @@
 
 /* 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();
@@ -572,10 +572,10 @@
 */
 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
