NullReferenceException during InternalApplyTableChangesAsync on MariaDB 10.11.8 and Dotmim.Sync v0.9.8

[DevDiapath]

I'm encountering a NullReferenceException during synchronization using Dotmim.Sync v0.9.8 with a MariaDB backend. The error occurs during the InternalApplyTableChangesAsync phase.

Error log:

Dotmim.Sync.Web.Client.HttpSyncWebException:
[InternalApplyThenGetChangesAsync]..[InternalApplyThenGetChangesAsync]..[InternalApplyChangesAsync]..[InternalApplyTableChangesAsync]..
Object reference not set to an instance of an object.

Stack trace:

at Dotmim.Sync.SyncAgent.<SynchronizeAsync>d__28.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at Dotmim.Sync.SyncAgent.<SynchronizeAsync>d__28.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at WebMonitorConnectorService.Helpers.SyncWeb.SyncWebHelper.SyncMariaDB(...) in SyncWebHelper.cs:line 133

Attachment:
SyncWebHelper.cs.txt

Line 133 is:
var result = agent.SynchronizeAsync(SyncType.Normal).GetAwaiter().GetResult();

Environment:

Dotmim.Sync version: 0.9.8 (tested also with 1.3.0)
Database: MariaDB 10.11.8 client and server
Client: .NET 4.8.0 and server .NET Core 8.0
Sync direction: Only Upload Client to Server
Provisioning: via SyncAgent.SynchronizeAsync()

[DevDiapath]

After debugging in the local environment, I discovered that the generated procedure for updating a table throws the NullReferenceException error on a DOUBLE UNSIGNED column in MariaDB. It also seems that the library does not handle DOUBLE UNSIGNED types properly. I have also tested this with the latest version of the library, but the issue persists!

[Mimetis]

Do you have an example of a table (for MariaDB) that throws the error ?
I just need the table schema (the sql query) that I could use to test ?

[DevDiapath]

Thank you for your reply.
Attached you'll find the SQL dump of the database server from one of our machines (without data). The issue lies in the tank table, specifically the volume column, which is defined as double unsigned. As a result, the tank_update procedure (generated by the library and included in the file) throws a null error during the update phase!
No issues occur with fields defined as "int unsigned".
For now, I’ve resolved it by removing "unsigned" from the "in_volume" field definition in the procedure tank_update at line 4325.

Thanks in advance for your support, and congratulations on the synchronization library — I believe it's the best ever created!
Alberto Basile

SN12345.sql.txt