Handle BadRequestTimeout gracefully in Publish error handling

[Copilot]

Proposed changes

The client logs BadRequestTimeout (0x80850000) as "Unhandled error during Publish" when servers return timeout responses to Publish requests. Per OPC UA spec, publish timeouts are expected operational behavior, not errors.

Change: Add StatusCodes.BadRequestTimeout to the switch statement in Session.OnPublishComplete() alongside StatusCodes.BadTimeout. Both now break to QueueBeginPublish(), which queues a new publish request without error logging.

case StatusCodes.BadTimeout:
case StatusCodes.BadRequestTimeout:  // Added
    break;

This eliminates spurious error logs while maintaining correct publish pipeline behavior.

Related Issues

Issue reference handled by system.

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• Enhancement (non-breaking change which adds functionality)
• Test enhancement (non-breaking change to increase test coverage)
• Breaking change (fix or feature that would cause existing functionality to not work as expected, requires version increase of Nuget packages)
• Documentation Update (if none of the other choices apply)

Checklist

• I have read the CONTRIBUTING doc.
• I have signed the CLA.
• I ran tests locally with my changes, all passed.
• I fixed all failing tests in the CI pipelines.
• I fixed all introduced issues with CodeQL and LGTM.
• I have added tests that prove my fix is effective or that my feature works and increased code coverage.
• I have added necessary documentation (if appropriate).
• Any dependent changes have been merged and published in downstream modules.

Further comments

Minimal single-line change. Existing tests cover the publish pipeline behavior; new behavior mirrors existing BadTimeout handling.

Original prompt

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This section details on the original issue you should resolve

<issue_title>[Client] PUBLISH x - Unhandled error 0x80850000 during Publish. --> Client should handle BadPublishTimeout code from the Server gracefully</issue_title>
<issue_description>Test logs are full of log entries like:

SubscriptionTest TransferSubscriptionOnlyAsync(DisconnectedRepublishDelayedAck,False,False)
	TEST 22:07:00.437 [Opc.Ua.Client.Session] PUBLISH OPCFoundation/UA-.NETStandard#10 - Unhandled error 0x80850000 during Publish.
	[AggregateException] One or more errors occurred.
	---    at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
	---    at Opc.Ua.Client.Session.OnPublishComplete(Task`1 task, NodeId sessionId, SubscriptionAcknowledgementCollection acknowledgementsToSend, RequestHeader requestHeader) in /_/Libraries/Opc.Ua.Client/Session/Session.cs:line 3444
	>>>> (Inner OPCFoundation/UA-.NETStandard#1) >>>>
	[ServiceResultException] [80850000]
	---    at Opc.Ua.Bindings.ChannelAsyncOperation`1.<EndAsync>d__12.MoveNext() in /_/Stack/Opc.Ua.Core/Stack/Tcp/ChannelAsyncOperation.cs:line 317
	--- --- End of stack trace from previous location where exception was thrown ---
	---    at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
	---    at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
	---    at Opc.Ua.Bindings.UaSCUaBinaryClientChannel.<SendRequestAsync>d__4.MoveNext() in /_/Stack/Opc.Ua.Core/Stack/Tcp/UaSCBinaryClientChannel.cs:line 339
	--- --- End of stack trace from previous location where exception was thrown ---
	---    at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
	---    at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
	---    at Opc.Ua.SessionClient.<PublishAsync>d__127.MoveNext() in /_/Stack/Opc.Ua.Core/Stack/Generated/Opc.Ua.Client.cs:line 10490
SubscriptionTest TransferSubscriptionOnlyAsync(DisconnectedRepublishDelayedAck,False,False)
	TEST 22:07:00.437 [Opc.Ua.Client.Session] PUBLISH OPCFoundation/UA-.NETStandard#8 - Unhandled error 0x80850000 during Publish.
	[AggregateException] One or more errors occurred.
	---    at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
	---    at Opc.Ua.Client.Session.OnPublishComplete(Task`1 task, NodeId sessionId, SubscriptionAcknowledgementCollection acknowledgementsToSend, RequestHeader requestHeader) in /_/Libraries/Opc.Ua.Client/Session/Session.cs:line 3444
	>>>> (Inner OPCFoundation/UA-.NETStandard#1) >>>>
	[ServiceResultException] [80850000]
	---    at Opc.Ua.Bindings.ChannelAsyncOperation`1.<EndAsync>d__12.MoveNext() in /_/Stack/Opc.Ua.Core/Stack/Tcp/ChannelAsyncOperation.cs:line 317
	--- --- End of stack trace from previous location where exception was thrown ---
	---    at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
	---    at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
	---    at Opc.Ua.Bindings.UaSCUaBinaryClientChannel.<SendRequestAsync>d__4.MoveNext() in /_/Stack/Opc.Ua.Core/Stack/Tcp/UaSCBinaryClientChannel.cs:line 339
	--- --- End of stack trace from previous location where exception was thrown ---
	---    at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
	---    at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
	---    at Opc.Ua.SessionClient.<PublishAsync>d__127.MoveNext() in /_/Stack/Opc.Ua.Core/Stack/Generated/Opc.Ua.Client.cs:line 10490

Those indicate a BadPublishTimeout StatusCode returned from the Server. Such StatusCodes need to be handled gracefully by the Client, as those are expected to be returned by the server.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes [Client] PUBLISH x - Unhandled error 0x80850000 during Publish. --> Client should handle BadPublishTimeout code from the Server gracefully #3459

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