Add a comment so the non-obvious work around doesn't get housecleaned.

devendor · devendor · commit 1fabfcda692f · 2018-10-01T16:02:11.000Z
diff --git a/msgpack/fallback.py b/msgpack/fallback.py
@@ -297,6 +297,7 @@ def feed(self, next_bytes):
             self._buff_i -= self._buf_checkpoint
             self._buf_checkpoint = 0
 
+        # Use extend here: INPLACE_ADD += doesn't reliably typecast memoryview in jython
         self._buffer.extend(view)
 
     def _consume(self):
