Return a negative parameter description if no parameters have been described while parsing

[jeroenrinzema]

After debugging the issue (#49) reported by @kishaningithub. I noticed that it is possible to not define the parameters by simply sending a out of bound/negative integer when describing a prepared message. This could probably be embedded by updating the writeParameterDescriptions to return a negative integer when no parameters are defined and to update the simple query option to simply not return any parameters.

psql-wire/command.go

Lines 294 to 303 in 8f291e8

	func (srv *Server) writeParameterDescriptions(writer *buffer.Writer, parameters []oid.Oid) error {
	writer.Start(types.ServerParameterDescription)
	writer.AddInt16(int16(len(parameters)))
	for _, parameter := range parameters {
	writer.AddInt32(int32(parameter))
	}
	return writer.End()
	}

psql-wire/options.go

Lines 71 to 92 in 8f291e8

	// NOTE: we have to lookup all parameters within the given query.
	// Parameters could represent positional parameters or anonymous
	// parameters. We return a zero parameter oid for each parameter
	// indicating that the given parameters could contain any type. We
	// could safely ignore the err check while converting given
	// parameters since ony matches are returned by the positional
	// parameter regex.
	matches := QueryParameters.FindAllStringSubmatch(query, -1)
	parameters := make([]oid.Oid, 0, len(matches))
	for _, match := range matches {
	// NOTE: we have to check whether the returned match is a
	// positional parameter or an un-positional parameter.
	// SELECT * FROM users WHERE id = ?
	if match[1] == "" {
	parameters = append(parameters, 0)
	}
	position, _ := strconv.Atoi(match[1]) //nolint:errcheck
	if position > len(parameters) {
	parameters = parameters[:position]
	}
	}