Throwing NullReferenceException when passing null parameter value to Query (MySqlParameter)

[alanprot]

To reproduce :

const string query = "select Col1 from Table1 where @parameter is null OR Col2 = @parameter";

using (var cmd = new MySqlCommand(query, con))
{
    cmd.Parameters.Add(new MySqlParameter() { ParameterName = "@parameter", Value = null });
    await cmd.ExecuteNonQueryAsync(cancellationToken);
}

Stack Trace:

at System.Object.GetType()
   at MySql.Data.MySqlClient.MySqlParameter.AppendSqlString(BinaryWriter writer, StatementPreparerOptions options)
   at MySql.Data.MySqlClient.MySqlStatementPreparer.ParameterSqlParser.DoAppendParameter(Int32 parameterIndex, Int32 textIndex, Int32 textLength)
   at MySql.Data.MySqlClient.MySqlParser.Parse(String sql)
   at MySql.Data.MySqlClient.MySqlStatementPreparer.ParseAndBindParameters()
   at MySql.Data.MySqlClient.MySqlCommand.<ExecuteReaderAsync>d__50.MoveNext()

[bgrainger]

Fixed in 0.6.2.