Fix BadContinuationPointInvalid that occurred due to incorrect Browser.BrowseAsync - #4167
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marcschier merged 1 commit intoAug 3, 2026
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…ng of an empty continuation point byte array in Browser.BrowseAsync
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The merge commit for this PR was removed from Maintenance fixes for the 1.5.378 lineage have to land on Thanks @KarenKrill for the fix - the commit in #4168 credits you as co-author. |
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… Browser.BrowseAsync (#4168) Re-submission of #4167 against `master378`. # Description #4167 was merged directly into `release/1.5.378`. Maintenance fixes for the 1.5.378 lineage have to land on `master378` first, so the commit was removed from `release/1.5.378` again and the fix is submitted here instead. Servers 1.6.0 and higher return a **zero length** continuation point in the `Browse` response to indicate that no further references are available. `Browser.BrowseAsync` only checked the continuation point for `null`, so it issued a `BrowseNext` call with an empty continuation point, which the server rejects with `BadContinuationPointInvalid`. The fix follows the continuation point only if it actually contains data. This is consistent with the already existing `continuationPoint?.Length > 0` check in the `OperationCanceledException` filter of the same method. Credit for the original fix goes to @KarenKrill (#4167). ## Related Issues - Fixes #3698 - Supersedes #4167 ## Checklist - [x] I have signed the [CLA](https://opcfoundation.org/license/cla/ContributorLicenseAgreementv1.0.pdf) and read the [CONTRIBUTING](https://github.com/OPCFoundation/UA-.NETStandard/blob/master/CONTRIBUTING.md) doc. - [x] I have added tests that prove my fix is effective or that my feature works and increased code coverage. - [x] I have added all necessary documentation. - [x] I have verified that my changes do not introduce (new) build or analyzer warnings. - [x] I ran the affected tests locally. - [ ] I fixed **all** failing and flaky tests in the CI pipelines and **all** CodeQL warnings. - [ ] I have addressed **all** PR feedback received. ## Further comments New unit tests in `Tests/Opc.Ua.Client.Tests/BrowserUnitTests.cs` pin the behaviour for `null`, empty and non empty continuation points. Verified that the new tests fail without the one line change and pass with it: `dotnet test Tests\Opc.Ua.Client.Tests\Opc.Ua.Client.Tests.csproj -f net10.0 --filter "FullyQualifiedName~BrowserUnitTests"` -> `Failed: 0, Passed: 3` The issue does not exist on `master` (2.0), where the `ByteString` refactoring already handles this. Co-authored-by: KarenKrill <74286712+KarenKrill@users.noreply.github.com> Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 75db5878-10f9-4099-993a-5eb969fa080e
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Fix BadContinuationPointInvalid that occurred due to incorrect handling of an empty continuation point byte array in Browser.BrowseAsync
Description
Temporary hotfix of BadContinuationPointInvalid when calling Browser.BrowseAsync with servers 1.6.0 and higher.
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The issue seems to be fixed by a refactoring in the master branch (adding the ByteString type), but I'm proposing a temporary spot hotfix for latest 1.5.378 version