PYTHON-1930 Fix pure python decoder support for memoryviews

Author: ShaneHarvey

bson/__init__.py

@@ -177,10 +177,6 @@ def get_data_and_view(data):
     def get_data_and_view(data):
         if isinstance(data, _supported_buffer_types):
             return data, memoryview(data)
-        elif isinstance(data, memoryview):
-            if isinstance(
-                    getattr(data, 'obj', None), _supported_buffer_types):
-                return data.obj, data
         view = memoryview(data)
         return view.tobytes(), view
 

test/test_bson.py

@@ -292,6 +292,7 @@ def test_decode_all_buffer_protocol(self):
         bs = b"".join(map(BSON.encode, docs))
         self.assertEqual(docs, decode_all(bytearray(bs)))
         self.assertEqual(docs, decode_all(memoryview(bs)))
+        self.assertEqual(docs, decode_all(memoryview(b'1' + bs + b'1')[1:-1]))
         if PY3:
             import array
             import mmap
@@ -307,6 +308,7 @@ def test_decode_buffer_protocol(self):
         self.assertEqual(doc, decode(bs))
         self.assertEqual(doc, decode(bytearray(bs)))
         self.assertEqual(doc, decode(memoryview(bs)))
+        self.assertEqual(doc, decode(memoryview(b'1' + bs + b'1')[1:-1]))
         if PY3:
             import array
             import mmap