A negative value returned means null no matter what value was actually

sent!

Author: anthony-tuininga

src/oracledb/impl/thin/messages.pyx

@@ -613,7 +613,7 @@ cdef class MessageWithData(Message):
                               name=var_impl.dbtype.name)
         if not self.in_fetch:
             buf.read_sb4(&actual_num_bytes)
-            if actual_num_bytes < 0 and column_value is False:
+            if actual_num_bytes < 0 and ora_type_num == TNS_DATA_TYPE_BOOLEAN:
                 column_value = None
             elif actual_num_bytes != 0 and column_value is not None:
                 unit_type = "bytes" if isinstance(column_value, bytes) \