Mysql 5.6, output MysqlParameter, binary(16) -> Guid conversion issue

[stretyak]

Software versions
MySqlConnector version: 2.3.7
Server type (MySQL, MariaDB, Aurora, etc.) and version: Mysql 5.6
.NET version: any

Describe the bug
Mysql 5.6 stores guids in binary format. binary(16)
When you define a guid output parameter mysqlconnector cannot convert byte[] received from mysql to Guid.
Because it tries to convert it via ToString -> Parse

Exception

System.FormatException
  HResult=0x80131537
  Message=Guid should contain 32 digits with 4 dashes (xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx).
  Source=System.Private.CoreLib
  StackTrace:
   at System.Guid.GuidResult.SetFailure(Boolean overflow, String failureMessageID)
   at System.Guid.TryParseExactN(ReadOnlySpan`1 guidString, GuidResult& result)
   at System.Guid.TryParseGuid(ReadOnlySpan`1 guidString, GuidResult& result)
   at System.Guid.Parse(String input)
   at MySqlConnector.Core.TypeMapper.<>c.<.ctor>b__3_13(Object o) in C:\git\MySqlConnector\src\MySqlConnector\Core\TypeMapper.cs:line 114
   at MySqlConnector.Core.DbTypeMapping.DoConversion(Object obj) in C:\git\MySqlConnector\src\MySqlConnector\Core\DbTypeMapping.cs:line 14
   at MySqlConnector.MySqlDataReader.<ReadOutParametersAsync>d__111.MoveNext() in C:\git\MySqlConnector\src\MySqlConnector\MySqlDataReader.cs:line 671
   at MySqlConnector.MySqlDataReader.<InitAsync>d__107.MoveNext() in C:\git\MySqlConnector\src\MySqlConnector\MySqlDataReader.cs:line 486
   at MySqlConnector.Core.CommandExecutor.<ExecuteReaderAsync>d__0.MoveNext() in C:\git\MySqlConnector\src\MySqlConnector\Core\CommandExecutor.cs:line 56
   at System.Threading.Tasks.ValueTask`1.get_Result()
   at System.Runtime.CompilerServices.ConfiguredValueTaskAwaitable`1.ConfiguredValueTaskAwaiter.GetResult()
   at MySqlConnector.MySqlCommand.<ExecuteNonQueryAsync>d__78.MoveNext() in C:\git\MySqlConnector\src\MySqlConnector\MySqlCommand.cs:line 309
   at System.Threading.Tasks.ValueTask`1.get_Result()
   at MySqlConnector.MySqlCommand.ExecuteNonQuery() in C:\git\MySqlConnector\src\MySqlConnector\MySqlCommand.cs:line 108
   at ConsoleApp3.Program.TestNullOutParam(String connStr) in C:\git\MySqlConnector\ConsoleApp3\Program.cs:line 52
   at ConsoleApp3.Program.Main(String[] args) in C:\git\MySqlConnector\ConsoleApp3\Program.cs:line 16

Code sample

var p = new MySqlParameter("@name1", MySqlDbType.Guid);
p.Direction = System.Data.ParameterDirection.Output;
cmd.Parameters.Add(p);
cmd.ExecuteNonQuery();

stored proc sample:

DROP PROCEDURE IF EXISTS `aa_test_out_par`$$

CREATE PROCEDURE `aa_test_out_par`
(
	OUT v_OrigID BINARY(16) 
)
BEGIN
	SELECT id INTO v_OrigID FROM ....

END$$

v_OrigID is guid stored in binary(16)

Expected behavior
it is expected when byte[] is recieved from Mysql side and the output parameter type is Guid
then mysqlconnector should create guid from byte[] like New Guid(byte[]) instead of converting the object to string and parsing back to Guid.

[bgrainger]

The default GUID format is Char36. If you want to store GUIDs as binary, set GUID Format=Binary16 in your connection string.

https://mysqlconnector.net/connection-options/#GuidFormat

[stretyak]

Neither LittleEndianBinary16 nor Binary16 specified in the connection string works.
there are no issues with the data received using a reader. it works fine with LittleEndianBinary16.
The problem is only with output parameters.
but there is a workaround
var p = new MySqlParameter("@name1", MySqlDbType.Binary) works.
and then to create manually the guid from byte[]