From 60b183407cbcd19b211c2dd7ed9a59ff189844a8 Mon Sep 17 00:00:00 2001 From: Antoine Pitrou Date: Thu, 3 Oct 2013 19:55:41 +0200 Subject: Issue #19014: memoryview.cast() is now allowed on zero-length views. --- Lib/test/test_buffer.py | 13 ++++++++++--- Misc/NEWS | 2 ++ Objects/memoryobject.c | 2 +- 3 files changed, 13 insertions(+), 4 deletions(-) diff --git a/Lib/test/test_buffer.py b/Lib/test/test_buffer.py index 747e2a2..04e3f61 100644 --- a/Lib/test/test_buffer.py +++ b/Lib/test/test_buffer.py @@ -2432,15 +2432,22 @@ class TestBufferProtocol(unittest.TestCase): self.assertRaises(ValueError, get_contiguous, nd[::-1], PyBUF_READ, 'C') def test_memoryview_cast_zero_shape(self): - # Casts are undefined if shape contains zeros. These arrays are - # regarded as C-contiguous by Numpy and PyBuffer_GetContiguous(), - # so they are not caught by the test for C-contiguity in memory_cast(). + # Casts are undefined if buffer is multidimensional and shape + # contains zeros. These arrays are regarded as C-contiguous by + # Numpy and PyBuffer_GetContiguous(), so they are not caught by + # the test for C-contiguity in memory_cast(). items = [1,2,3] for shape in ([0,3,3], [3,0,3], [0,3,3]): ex = ndarray(items, shape=shape) self.assertTrue(ex.c_contiguous) msrc = memoryview(ex) self.assertRaises(TypeError, msrc.cast, 'c') + # Monodimensional empty view can be cast (issue #19014). + for fmt, _, _ in iter_format(1, 'memoryview'): + msrc = memoryview(b'') + m = msrc.cast(fmt) + self.assertEqual(m.tobytes(), b'') + self.assertEqual(m.tolist(), []) def test_memoryview_struct_module(self): diff --git a/Misc/NEWS b/Misc/NEWS index ad44fe7..794e94f 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -12,6 +12,8 @@ What's New in Python 3.3.3 release candidate 1? Core and Builtins ----------------- +- Issue #19014: memoryview.cast() is now allowed on zero-length views. + - Issue #19098: Prevent overflow in the compiler when the recursion limit is set absurdly high. diff --git a/Objects/memoryobject.c b/Objects/memoryobject.c index abd069b..189af88 100644 --- a/Objects/memoryobject.c +++ b/Objects/memoryobject.c @@ -1330,7 +1330,7 @@ memory_cast(PyMemoryViewObject *self, PyObject *args, PyObject *kwds) "memoryview: casts are restricted to C-contiguous views"); return NULL; } - if (zero_in_shape(self)) { + if ((shape || self->view.ndim != 1) && zero_in_shape(self)) { PyErr_SetString(PyExc_TypeError, "memoryview: cannot cast view with zeros in shape or strides"); return NULL; -- cgit v0.12