Exception when executing with custom type parameter and at least one of its fields is null

Hello everyone!

We have a stored procedure that takes custom type parameter on the input. If we set one of the fields of this type to null described exception happens.

Custom type example:

CREATE TYPE TItem AS
(
	ID int,
	ParentID smallint
);

SP example:

CREATE OR REPLACE FUNCTION spSaveItem(
	_Item TItem
) 
RETURNS void AS
$BODY$
BEGIN
	-- any process code
END;
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;

Code example:

using (var cmd = new NpgsqlCommand("spSaveItem", conn))
{
    cmd.CommandType = CommandType.StoredProcedure;
    cmd.Parameters.Add(new NpgsqlParameter()
            {
                ParameterName = "_Item",
                Value = new { ID = 5, ParentID = null },
                DataTypeName = $"public.TItem",
            });
    cmd.ExecuteNonQuery();
}

Same thing happens if set ParentID to DBNull.Value.

Result is:

Exception message: 08P01:  invalid frontend message type 1
Stack trace:
NpgsqlDataReader.NextResult(Boolean async, Boolean isConsuming)
    NpgsqlDataReader.NextResult()
    NpgsqlCommand.ExecuteReaderAsync(CommandBehavior behavior, Boolean async, CancellationToken cancellationToken)
    NpgsqlCommand.ExecuteReader(CommandBehavior behavior)

Npgsql version: 4.1.3 PostgreSQL version: 12.1 Operating system: Ubuntu 12.1

[andrewvanpersie]

Thank you guys, you’re doing really a tremendous job! Hope you’re well and safe!

[roji]

@YohDeadfall modified the milestone to 4.1.4. Since github allows only one milestone to be select on an issue, I think it’s better to use it to express the latest stable patch release where the fix was merged (users can scan the issue to see other versions as well).