memslice decref old item on item assignment

Cython/Compiler/ExprNodes.py

@@ -4029,12 +4029,12 @@ class AttributeNode(ExprNode):
             code.put_gotref(self.py_result())
         elif self.type.is_memoryviewslice:
             if self.initialized_check:
-                code.putln(textwrap.dedent('''
-                    if (unlikely(!%s.memview)) {
-                        PyErr_SetString(PyExc_AttributeError,
-                                        "Memoryview is not initialized");
-                        %s
-                    }''' % (self.result(), code.error_goto(self.pos))))
+                code.putln(
+                    'if (unlikely(!%s.memview)) {'
+                        'PyErr_SetString(PyExc_AttributeError,'
+                                        '"Memoryview is not initialized");'
+                        '%s'
+                    '}' % (self.result(), code.error_goto(self.pos)))
             #code.putln("%s = %s;" % (self.result(),
             #                         self.calculate_result_code()))
         else:

Cython/Utility/MemoryView.pyx

@@ -310,9 +310,9 @@ cdef class _memoryviewslice(memoryview):
 
     cdef convert_item_to_object(self, char *itemp):
         if self.to_object_func != NULL:
-            self.to_object_func(itemp)
+            return self.to_object_func(itemp)
         else:
-            memoryview.convert_item_to_object(self, itemp)
+            return memoryview.convert_item_to_object(self, itemp)
 
     cdef assign_item_from_object(self, char *itemp, object value):
         if self.to_dtype_func != NULL:
@@ -328,7 +328,8 @@ cdef memoryview_cwrapper(object o, int flags):
 @cname('__pyx_memoryview_fromslice')
 cdef memoryview_from_memslice_cwrapper(
             {{memviewslice_name}} *memviewslice, object orig_obj, int flags, int cur_ndim,
-             object (*to_object_func)(char *), int (*to_dtype_func)(char *, object)):
+             object (*to_object_func)(char *),
+             int (*to_dtype_func)(char *, object) except 0):
     cdef _memoryviewslice result = _memoryviewslice(orig_obj, flags)
     cdef int new_ndim = result.view.ndim - cur_ndim
 
@@ -340,6 +341,7 @@ cdef memoryview_from_memslice_cwrapper(
     result.view.ndim = cur_ndim
 
     result.to_object_func = to_object_func
+    result.to_dtype_func = to_dtype_func
 
     return result
 
@@ -382,7 +384,7 @@ cdef char *pybuffer_index(Py_buffer *view, char *bufp, Py_ssize_t index, int dim
         if index < 0:
             raise IndexError("Out of bounds on buffer access (axis %d)" % dim)
 
-    if index > shape:
+    if index >= shape:
         raise IndexError("Out of bounds on buffer access (axis %d)" % dim)
 
     resultp = bufp + index * stride

Cython/Utility/MemoryView_C.c

@@ -452,6 +452,7 @@ PyObject *{{get_function}}(const char *itemp) {
 
 int {{set_function}}(const char *itemp, PyObject *obj) {
     Py_INCREF(obj);
+    Py_DECREF(*(PyObject **) itemp);
     *(PyObject **) itemp = obj;
     return 1;
 }

tests/run/memoryview.pyx

@@ -127,7 +127,7 @@ def test_cdef_attribute():
 
     print ExtClass().mview
 
-
+'''
 def basic_struct(MyStruct[:] mslice):
     """
     See also buffmt.pyx
@@ -218,7 +218,7 @@ def complex_struct_inplace(LongComplex[:] mslice):
     buf[0].real += 1
     buf[0].imag += 2
     print buf[0].real, buf[0].imag
-
+'''
 #
 # Getting items and index bounds checking
 #
@@ -227,6 +227,8 @@ def get_int_2d(int[:, :] mslice, int i, int j):
     >>> C = IntMockBuffer("C", range(6), (2,3))
     >>> get_int_2d(C, 1, 1)
     acquired C
+    acquired C
+    released C
     released C
     4
 
@@ -342,6 +344,8 @@ def writable(unsigned short int[:, :, :] mslice):
     >>> R = UnsignedShortMockBuffer("R", range(27), shape=(3, 3, 3))
     >>> writable(R)
     acquired R
+    acquired R
+    released R
     released R
     >>> [str(x) for x in R.recieved_flags] # Py2/3
     ['FORMAT', 'ND', 'STRIDES', 'WRITABLE']
@@ -354,6 +358,8 @@ def strided(int[:] mslice):
     >>> A = IntMockBuffer("A", range(4))
     >>> strided(A)
     acquired A
+    acquired A
+    released A
     released A
     2
 
@@ -412,12 +418,16 @@ def generic(int[::view.generic, ::view.generic] mslice1,
     >>> generic(A, B)
     acquired A
     acquired B
+    acquired A
+    acquired B
     4
     4
     10
     11
     released A
     released B
+    released A
+    released B
     """
     buf1, buf2 = mslice1, mslice2
 
@@ -438,12 +448,16 @@ def generic_contig(int[::view.generic_contiguous, :] mslice1,
     >>> generic_contig(A, B)
     acquired A
     acquired B
+    acquired A
+    acquired B
     4
     4
     10
     11
     released A
     released B
+    released A
+    released B
     """
     buf1, buf2 = mslice1, mslice2