Always enable auto retry (#753)

* test using auto retry

* add/update changelog and add comment

* wordsmithing

* Update CHANGELOG.rst

* Update CHANGELOG.rst
diff --git a/src/OpenSSL/SSL.py b/src/OpenSSL/SSL.py
index f3c9db0..1bf6450 100644
--- a/src/OpenSSL/SSL.py
+++ b/src/OpenSSL/SSL.py
@@ -1529,6 +1529,11 @@
 
         ssl = _lib.SSL_new(context._context)
         self._ssl = _ffi.gc(ssl, _lib.SSL_free)
+        # We set SSL_MODE_AUTO_RETRY to handle situations where OpenSSL returns
+        # an SSL_ERROR_WANT_READ when processing a non-application data packet
+        # even though there is still data on the underlying transport.
+        # See https://github.com/openssl/openssl/issues/6234 for more details.
+        _lib.SSL_set_mode(self._ssl, _lib.SSL_MODE_AUTO_RETRY)
         self._context = context
         self._app_data = None