Insert Ignore LastInsertedId is -1 when Ignored

[mkehoe]

Software versions
MySqlConnector version: 2.1.7
Server type (MySQL, MariaDB, Aurora, etc.) and version: MySql 5.7
.NET version: 6.0

Describe the bug
When using an insert ignore statement with ExecuteNonQueryAsync(), LastInsertedId is -1 (expected 0) if the insert is ignored. I believe this is changed behavior from an earlier version.

Code sample

await connection.OpenAsync();

var sql = @"insert ignore into test.test_table (id, foo) values (@id, @foo)";
await using var cmd = new MySqlCommand(sql, connection);

cmd.Parameters.AddWithValue("@id", 2);
cmd.Parameters.AddWithValue("@foo", "Test");

cmd.CommandType = System.Data.CommandType.Text;
await cmd.ExecuteNonQueryAsync();

Expected behavior
MySqlConnector docs for LastInsertedId reference MySql LAST_INSERTED_ID() and they state:

If you use INSERT IGNORE and the row is ignored, the LAST_INSERT_ID() remains unchanged from the current value (or 0 is returned if the connection has not yet performed a successful INSERT)

This statement leads me to believe that 0 for LastInsertedId is correct in this scenario.

[bgrainger]

I believe this is changed behavior from an earlier version.

It looks like the value of cmd.LastInsertedId (in this example) changed from 0 to -1 between 1.3.14 and 2.0.0.

[bgrainger]

This may have been a regression introduced by the fix for #1026.

[bgrainger]

Fixed in 2.1.8.