fixup! support for readonly buffers (#863)

Author: skoslowski

include/pybind11/detail/class.h

@@ -486,7 +486,7 @@ extern "C" inline int pybind11_getbuffer(PyObject *obj, Py_buffer *view, int fla
         view->len *= s;
     view->readonly = info->readonly;
     if ((flags & PyBUF_WRITABLE) == PyBUF_WRITABLE && info->readonly) {
-        if(view)
+        if (view)
             view->obj = nullptr;
         PyErr_SetString(PyExc_BufferError, "Writable buffer requested for readonly storage");
         return -1;

tests/test_buffers.py

@@ -1,9 +1,14 @@
 import io
 import struct
+import sys
+
 import pytest
+
 from pybind11_tests import buffers as m
 from pybind11_tests import ConstructorStats
 
+PY3 = sys.version_info[0] >= 3
+
 pytestmark = pytest.requires_numpy
 
 with pytest.suppress(ImportError):
@@ -92,22 +97,22 @@ def test_pointer_to_member_fn():
 def test_readonly_buffer():
     buf = m.BufferReadOnly(0x64)
     view = memoryview(buf)
-    assert view[0] == 0x64
+    assert view[0] == 0x64 if PY3 else b'd'
     assert view.readonly
 
 
 @pytest.unsupported_on_pypy
 def test_selective_readonly_buffer():
     buf = m.BufferReadOnlySelect()
 
-    memoryview(buf)[0] = 0x64
+    memoryview(buf)[0] = 0x64 if PY3 else b'd'
     assert buf.value == 0x64
 
     io.BytesIO(b'A').readinto(buf)
     assert buf.value == ord(b'A')
 
     buf.readonly = True
     with pytest.raises(TypeError):
-        memoryview(buf)[0] = 0
+        memoryview(buf)[0] = 0 if PY3 else b'\0'
     with pytest.raises(TypeError):
         io.BytesIO(b'1').readinto(buf)