BUG: iter: Fix code and test for NPY_NO_CASTING case

4 files changed, 21 insertions, 11 deletions

diff --git a/numpy/core/src/multiarray/new_iterator.c.src b/numpy/core/src/multiarray/new_iterator.c.src
index 985e7d084..9a59379b0 100644
--- a/numpy/core/src/multiarray/new_iterator.c.src
+++ b/numpy/core/src/multiarray/new_iterator.c.src
@@ -2016,7 +2016,14 @@ npyiter_can_cast(PyArray_Descr *from, PyArray_Descr *to, NPY_CASTING casting)
             }
             return ret;
         }
-        return 1;
+
+        if (casting == NPY_NO_CASTING) {
+            return PyArray_ISNBO(from->byteorder) ==
+                   PyArray_ISNBO(to->byteorder);
+        }
+        else {
+            return 1;
+        }
     }
     /* If safe or same-kind casts are allowed */
     else if (casting == NPY_SAFE_CASTING || casting == NPY_SAME_KIND_CASTING) {
diff --git a/numpy/core/src/multiarray/new_iterator.h b/numpy/core/src/multiarray/new_iterator.h
index 26370d8f2..90949471a 100644
--- a/numpy/core/src/multiarray/new_iterator.h
+++ b/numpy/core/src/multiarray/new_iterator.h
@@ -14,16 +14,16 @@ typedef void (*NpyIter_GetCoords_Fn )(NpyIter *iter,
 
 /* For specifying allowed casting in operations which support it */
 typedef enum {
-        /* Only allow exactly equivalent types */
+        /* Only allow identical types */
         NPY_NO_CASTING=0,
-        /* Allow casts between equivalent types of different byte orders  */
-        NPY_EQUIV_CASTING=0,
+        /* Allow identical and byte swapped types */
+        NPY_EQUIV_CASTING=1,
         /* Only allow safe casts */
-        NPY_SAFE_CASTING=1,
+        NPY_SAFE_CASTING=2,
         /* Allow safe casts or casts within the same kind */
-        NPY_SAME_KIND_CASTING=2,
+        NPY_SAME_KIND_CASTING=3,
         /* Allow any casts */
-        NPY_UNSAFE_CASTING=3
+        NPY_UNSAFE_CASTING=4
 } NPY_CASTING;
 
 
diff --git a/numpy/core/src/multiarray/new_iterator_pywrap.c b/numpy/core/src/multiarray/new_iterator_pywrap.c
index 757ddc709..9d43774cc 100644
--- a/numpy/core/src/multiarray/new_iterator_pywrap.c
+++ b/numpy/core/src/multiarray/new_iterator_pywrap.c
@@ -91,7 +91,7 @@ npyiter_init(NewNpyArrayIterObject *self, PyObject *args, PyObject *kwds)
     PyArrayObject *op[NPY_MAXARGS];
     npy_uint32 flags = 0;
     NPY_ORDER order = NPY_KEEPORDER;
-    NPY_CASTING casting = NPY_NO_CASTING;
+    NPY_CASTING casting = NPY_EQUIV_CASTING;
     npy_uint32 op_flags[NPY_MAXARGS];
     PyArray_Descr *op_request_dtypes[NPY_MAXARGS];
     npy_intp oa_ndim = 0;
diff --git a/numpy/core/tests/test_new_iterator.py b/numpy/core/tests/test_new_iterator.py
index 74affaebf..ad9b9226f 100644
--- a/numpy/core/tests/test_new_iterator.py
+++ b/numpy/core/tests/test_new_iterator.py
@@ -619,7 +619,8 @@ def test_iter_nbo_align():
     au = a.byteswap().newbyteorder()
     assert_(a.dtype.byteorder != au.dtype.byteorder)
     i = newiter(au, [], [['readwrite','updateifcopy']],
-                                            op_dtypes=[np.dtype('f4')])
+                        casting='equiv',
+                        op_dtypes=[np.dtype('f4')])
     assert_equal(i.dtypes[0].byteorder, a.dtype.byteorder)
     assert_equal(i.operands[0].dtype.byteorder, a.dtype.byteorder)
     assert_equal(i.operands[0], a)
@@ -631,7 +632,7 @@ def test_iter_nbo_align():
     a = np.arange(6, dtype='f4')
     au = a.byteswap().newbyteorder()
     assert_(a.dtype.byteorder != au.dtype.byteorder)
-    i = newiter(au, [], [['readwrite','updateifcopy','nbo_aligned']])
+    i = newiter(au, [], [['readwrite','updateifcopy','nbo_aligned']], casting='equiv')
     assert_equal(i.dtypes[0].byteorder, a.dtype.byteorder)
     assert_equal(i.operands[0].dtype.byteorder, a.dtype.byteorder)
     assert_equal(i.operands[0], a)
@@ -731,7 +732,7 @@ def test_iter_array_cast_errors():
                 op_dtypes=[np.dtype('f4')])
     # '<f4' -> '>f4' should not work with casting='no'
     assert_raises(TypeError, newiter, arange(2,dtype='<f4'), [],
-                [['readonly']], casting='no',
+                [['readonly','copy']], casting='no',
                 op_dtypes=[np.dtype('>f4')])
     # 'f4' -> 'f8' is a safe cast, but 'f8' -> 'f4' isn't
     assert_raises(TypeError, newiter, arange(2,dtype='f4'), [],
@@ -1134,6 +1135,7 @@ def test_iter_buffering():
             i = np.newiter(a, ['buffered','no_inner_iteration'],
                            [['readonly','nbo_aligned']],
                            order='C',
+                           casting='equiv',
                            buffersize=buffersize)
             while not i.finished:
                 assert_(i[0].size <= buffersize)
@@ -1148,6 +1150,7 @@ def test_iter_write_buffering():
     a = np.arange(24).reshape(2,3,4).T.newbyteorder().byteswap()
     i = np.newiter(a, ['buffered'],
                    [['readwrite','nbo_aligned']],
+                   casting='equiv',
                    order='C',
                    buffersize=16)
     x = 0