6 Commits

Author SHA1 Message Date
romanett 9b034f8291 Enable nullable reference types centrally; migrate all unset and annotations-only projects (#4700)
# Description

Nullable reference types are now enabled once, in `common.props`, and
every project in the repository builds warning-clean with them.

**Configuration**
- `<Nullable>enable</Nullable>` lives in `common.props`. All per-project
`<Nullable>` settings are removed: 178 project files (enable,
annotations, and the `disable` in the three Aot test projects).
- 419 per-file `#nullable enable`/`restore` directives and the 4
`#nullable disable` directives are removed.
- Kept on purpose:
- The 5 `<auto-generated>` schema files (`UANodeSet.cs`, `UA Type
Dictionary.cs`, `OPCBinarySchema.cs`, `SecuredApplication.cs`,
`PInvokeHelper.cs`) keep `#nullable enable`. The compiler ignores the
project setting in generated code, so the directive is required there.
- `tests/Opc.Ua.Interop.LegacyPeer` keeps `disable`. It builds against
the 1.5.378 packages and does not import the repository props.
- `docs/DeveloperGuide.md` and `.github/copilot-instructions.md` now
describe the central setting.

**Migration** (the 43 unset and 13 annotations-only projects, roughly
10k diagnostics)
- **Production code: annotated at the declarations.** Covers
`tools/Opc.Ua.SourceGeneration.Core`, `src/Opc.Ua.Lds.Server` and the
LDS sample.
- Members, parameters and returns are nullable where null actually
flows.
- Null-check helpers carry `[NotNullWhen]` (`IsNull`, `IsValidXmlName`,
`IsMethodTypeDesign`).
- `CoreUtils.Format`, `Utils.Format`, `ITemplateWriter.WriteLine` take
`params object?[]`. `Template.AddReplacement` takes `string?` (rendering
already skips null replacements).
- `IRegisteredServerStore.RegisterAsync` returns
`Task<RegistrationEntry?>`: it returns null when a registration is
removed.
- Dereferences backed by an invariant (for example, the validated model)
use `!`, so runtime behaviour is unchanged.
- **Behavioural changes in production code** (small, deliberate):
- `NodeSetToModelDesign` throws `InvalidOperationException` when the
file is not a NodeSet. Before, it threw a NullReferenceException on the
next line.
- `ModelDesignValidator` starts its lookup tables empty instead of null.
A redundant `if (m_nodes == null) return;` guard is gone.
- **Test code: minimal annotations.**
  - `?` on values that can be null, `!` where the test asserts non-null.
  - `= null!` for fixture members assigned in SetUp.
- `TryGetStructure<T>(out T? x)` where the inferred `T?` broke the
`IEncodeable` constraint.
- A few redundant `== null` checks on structs (`NodeId`, `ArrayOf<T>`)
folded into the adjacent `IsNull`/`Count` checks.

**Notes for reviewers**
- The diff is large (~1,500 files) but almost entirely mechanical: `?`,
`!` and directive removal. The non-annotation changes are listed above.
- Known follow-up, not done here:
`IModelDesign.Namespaces/TargetNamespace/NamespaceUris` stay
non-nullable even though the validator returns null before it loads a
dictionary. Making them nullable would ripple through every generator
call site.

## Related Issues

- Fixes #4439

## Checklist

- [ ] 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.
- [ ] 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.
- [ ] I ran **all** tests locally using the **UA.slnx** solution against
at least .net **framework** and .net **10**, and all passed.
- [ ] I fixed **all** failing and flaky tests in the CI pipelines and
**all** CodeQL warnings.
- [ ] I have addressed **all** PR feedback received.

The "no new warnings" box covers net10.0 and net48: full non-incremental
builds of `UA.slnx`, `tools/SourceGeneration.slnx`,
`tools/MigrationAnalyzer.slnx` and the Aot test projects finished with 0
warnings and 0 errors under the repository's warnings-as-errors
settings. net9.0 and net8.0 also had no nullable diagnostics, but they
were not rebuilt after the final fixes. Tests have not been run locally
yet.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-08 08:48:13 +02:00
romanett a0d569d756 Fix Server and GDS audit findings, review findings and spec-conformance gaps (#4571)
## Summary

Fixes the findings of a bug audit of `Opc.Ua.Server`,
`Opc.Ua.Gds.Server` and `Opc.Ua.Gds.Client`. Rebased on master after
#4516.

What went in:
- **Audit:** 93 findings, each checked against the OPC UA specification.
- **Code review of those fixes:** 35 further findings.
- **Spec grounding of every fix commit:** 18 conformance gaps, now
closed.

Commits are one per finding, named `Fix <ID>`, `Fix review <ID>` or `Fix
spec gap <name>`. The IDs refer to the audit report (S = Server areas,
G1 = GDS server, G2 = GDS client).

Validation:
- Each finding was traced in code and checked against OPC 10000 (parts
3, 4, 5, 9, 11, 12, 13, 18, 20).
- Every fix commit was checked against the spec text again afterwards: 0
non-conformant, remaining gaps fixed.
- Regression tests were added for most fixes.
- Suites run on net10.0 before the rebase: Server, GDS, History,
Configuration, Features, Core.Security, DI, Redundancy, LDS,
InformationModel, PubSub.Server, Client, Sessions and the three
Subscriptions suites, all green. The same suites on the rebased branch
are still running; results will be posted as a comment.

## Behaviour and user-facing changes

### Secure defaults
- **`Historize()` / `HistorianBuilder`** grant HistoryRead only. History
writes need an explicit `historyAccessLevel: HistoryRead |
HistoryWrite`.
- **File-system mount:**
- Anonymous sessions can no longer create, delete, move or open files
for writing (`Bad_UserAccessDenied`).
  - UserWritable and UserExecutable now reflect the user.
- `AllowAnonymousWrite` restores the old behaviour; the ReferenceServer
sample turns it on.
- **Default PKI root** for the hosted server, hosted GDS, hosted LDS and
`OpcUaApplicationConfigurationProvider`:
- Moved from the shared temp directory to `{LocalApplicationData}/OPC
Foundation/{ApplicationName}/pki`, and startup fails if no per-user
directory exists.
- When certificate stores of an earlier version still exist under temp,
a warning names both paths. Existing deployments that relied on the
default get a new application certificate (and the hosted GDS a new CA)
unless `PkiRoot` is set to the old path.
- **GDS:**
  - `GdsServerOptions.AutoApprove` defaults to `false`.
- The default KeyCredential store grants no roles unless
`AuthorizeRoles` allows them.
- Certificate requests (StartSigningRequest, StartNewKeyPairRequest,
FinishRequest) need an encrypted channel.
- **Hosted server anonymous logins:**
- Anonymous is rejected (`Bad_IdentityTokenRejected`) when the default
authenticator options disable it.
- A custom `AddIdentityAuthenticator<T>()` on its own no longer disables
anonymous.
- With anonymous disabled and no configured token policies, the endpoint
advertises the authenticators' token types instead of Anonymous.
- **Runtime-added roles:** their properties and methods need
SecurityAdmin over an encrypted channel, like the well-known roles.
- **Disabled users:** users disabled through Part 18 UserManagement can
no longer log in through `RegisterDefaultAuthenticators(IUserDatabase)`.

### GDS server (Part 12)
- **Certificate requests:**
- FinishRequest / ReadRequest with another application's RequestId
returns `Bad_InvalidArgument`.
  - Every Start*Request returns a new RequestId.
- A CSR without the ApplicationUri is rejected
(`Bad_CertificateUriInvalid`).
- An abstract or unsupported certificate type is rejected at Start
(`Bad_InvalidArgument`).
- **Private-key password:** no longer persisted in the JSON applications
database. A password saved by an earlier version is read into memory
once and dropped on the next save.
- **CheckRevocationStatus:** validates offline against the GDS's own
trust lists and CRLs. It returns Good for good GDS-issued certificates
and `Bad_CertificateInvalid` for input that is not a certificate.
- **Certificate-group trust lists:**
- Writes need CertificateAuthorityAdmin; SecurityAdmin and application
admins are read-only.
  - Writes are validated with the Part 4 certificate validation.
- **AuthorizationService:**
- The legacy RequestAccessToken applies `AccessControl` and issues the
token for the session identity.
- StartRequestToken passes the session identity to every identity-aware
provider.
  - Unknown ResourceIds return `Bad_NotFound`.
- Expired token requests and refresh tokens are pruned, with at most 10
000 pending requests (`Bad_TooManyOperations`).
- **KeyCredential:** requests with PublicKey + SecurityPolicyUri are
rejected with `Bad_SecurityPolicyRejected` (secret encryption is not
implemented); a PublicKey without SecurityPolicyUri is rejected with
`Bad_InvalidArgument`.
- **Audit events:** access-token audit events no longer contain the
password or token data.
- **RegisterTickets / UnregisterTickets:** need the RegistrarAdmin role
when called from a session.
- **Managed application nodes:** moved from namespace 0 to their own
namespace (`ManagedApplicationsNamespaceUri`); the NodeId is the
ApplicationUri, and the mandatory child properties exist.
- **Hosted GDS:**
- New `GdsServerOptions.CertificateGroups`
(`GdsCertificateGroupOptions`), bindable from configuration.
  - The mandatory DefaultApplicationGroup is always present.
  - The default CA subject uses the resolved application name.
- **JSON applications database:**
- A corrupt file throws instead of being silently replaced by an empty
database.
- Saves are atomic and write in place on bind mounts; on net8+ builds
they also follow symlinks and keep the Unix file mode.
  - Issued certificates and trust-list links survive a reload.

### GDS client
- **Trust-list download:**
  - Reads until an empty chunk (Part 20 short reads).
- A size-limit rejection of the final end-of-file read, as sent by
released servers, counts as end of file.
- **Default certificate group:** a null group means
DefaultApplicationGroup, and vendor groups in other namespaces are no
longer mistaken for well-known groups.
- **Status codes and errors:**
  - Missing directory proxies report `Bad_ServerNotConnected`.
- Short or wrongly typed method outputs throw `BadUnexpectedError` /
`BadTypeMismatch`.
- **GdsAccessTokenProvider:** no longer caches a failed client task, and
one caller's cancellation no longer fails other callers.

### Trust lists, push and ConfigurationFile (Part 12 / Part 20)
- **AddCertificate:**
  - `IsTrustedCertificate=false` returns `Bad_CertificateInvalid`.
- Added certificates are validated (Part 4), and a certificate revoked
by a current CRL returns `Bad_CertificateRevoked`.
- **CloseAndUpdate:** validates the uploaded list against its own
certificates and CRLs, not the stores it replaces. Validation failures
are no longer recorded in the server's Rejected store.
- **RemoveCertificate:** removing a trusted or issuer CA that other
certificates still need returns `Bad_CertificateChainIncomplete`.
- **Handles:**
  - Several read handles may be open at once.
- Any open while a write handle exists returns `Bad_NotReadable` /
`Bad_NotWritable`.
  - A write open while any handle is open returns `Bad_NotWritable`.
  - Handles of closed sessions are released.
  - Idle handles close after ActivityTimeout (default 60 s).
- **Status codes:**
- Read clamps to the remaining bytes and no longer enforces the size
limit.
  - Oversized Write / AddCertificate returns `Bad_RequestTooLarge`.
  - Unsupported open modes return `Bad_NotSupported`.
- **ConfigurationFile.CloseAndUpdate:**
  - Empty Targets return `Bad_InvalidArgument`.
- The ConfigurationUpdatedAuditEvent is raised with the configuration
owner as source.
- With the new `IApplicationConfigurationFileTargetProvider`, providers
receive the Targets, a bad target returns Uncertain with per-target
results, and session-interrupting updates are applied after
RestartDelayTime.
- **Default namespace permissions:** namespaces registered after the
first permission lookup now get their NamespaceMetadata default
RolePermissions and AccessRestrictions (no stale negative cache).

### Sessions, identity and roles (Part 18)
- **Session timeouts:** a failure closing one timed-out session no
longer stops the session-timeout monitor.
- **ChangePassword:** an empty old password returns
`Bad_IdentityTokenInvalid`.
- **Removing or disabling a user:** closes only that user's
UserName-token sessions.
- **Role configuration changes:** roles granted by an `ImpersonateUser`
mapping are kept.
- **X509Subject rules:** a certificate subject value containing a quote
never matches an X509Subject rule.
- **`ImpersonateUser` callback:** no longer runs under the global
session lock.
- **Session diagnostics:** LocaleIds are kept as the client sent them,
while null LocaleIds are ignored for translation.

### Subscriptions and monitored items (Part 4)
- **Acknowledgements:** a failing acknowledgement returns a per-entry
Bad status instead of failing the whole Publish.
- **`DiscardedMessageCount`:** counts messages dropped from the
retransmission queue and unsent overflow messages.
- **Durable subscriptions:** transferring a restored anonymous
subscription works (no NullReferenceException).
- **Transferred subscriptions:** sampling and permission checks use the
item's current owner session.
- **Access denied:** a monitored item whose user may no longer read the
attribute gets a `Bad_UserAccessDenied` notification instead of going
silent. Non-Value attributes need Browse permission (RolePermissions
needs ReadRolePermissions), and User* attributes are evaluated per
subscriber.
- **ModifyMonitoredItems:** a SamplingInterval of -1 uses the
subscription's publishing interval.
- **AggregateFilter priming:** needs HistoryRead / ReadHistory
permission and is bounded (100 000 values, bounded page size).
- **Resource leak:** event monitored items no longer leak a consumer
task per create/delete cycle.

### Node management services (Part 3 / Part 4)
- **Reference types:** AddNodes, AddReferences, DeleteReferences and
Browse reject ids that are not ReferenceTypes with
`Bad_ReferenceTypeIdInvalid`. AddNodes, AddReferences and
DeleteReferences also reject abstract ReferenceTypes; Browse still
accepts them (e.g. `HierarchicalReferences` with includeSubtypes).
- **Concurrent AddNodes:** duplicate BrowseNames under one parent get
`Bad_BrowseNameDuplicated`.
- **TranslateBrowsePathsToNodeIds:**
- Requires Browse permission on intermediate nodes and final targets
(RolePermissions and AccessRestrictions).
  - A long RelativePath no longer rejects the whole request.
- **SemanticChangeEvent:**
- Raised once per actual change of a semantic property, whether or not
it is monitored.
  - Also raised for properties with the SemanticChange access-level bit.
  - Reports the owning node's TypeDefinition as AffectedType.
- **Localized diagnostics:** operation-level text is translated when
OperationLocalizedText is requested.

### History and aggregates (Part 11 / Part 13)
- **DeleteRawModified:** an unspecified or reversed range returns
`Bad_InvalidTimestampArgument`, and StartTime == EndTime deletes the
value at StartTime for every provider.
- **ReadAtTime fallback:** reads only the values around each requested
time. A time whose bound is not found within the search limit returns
`Bad_BoundNotSupported` instead of failing the request.
- **ReadProcessed:** a ProcessingInterval shorter than one tick returns
`Bad_AggregateInvalidInputs`.
- **Delta / DeltaBounds:** widen to the next larger signed type when the
result does not fit the source type (e.g. a decreasing unsigned counter,
or an Int16 overflow).
- **Range / Range2:** return the source data type.

### Alarms and fluent API (Part 9)
- **Suppression:** an alarm stays suppressed while any suppression group
is active, and re-evaluation without a state change does not move
TransitionTime.
- **`MonitorVariable(variable)`:** sets SourceNode, SourceName and
InputNode to the variable and makes it a ConditionSource (HasCondition
to the alarm, HasEventSource from the object).
- **Fluent input/output arguments:** InputArguments / OutputArguments
added through the fluent API to a registered method are readable.
- **Root notifiers:** a failed root-notifier registration no longer
leaves an orphaned event worker.
- **State-machine handlers:** exceptions are logged at Error.

### File system (Part 20)
- **Delete / MoveOrCopy:**
  - Only act on direct children of the directory.
- A NodeId whose kind does not match the entry returns `Bad_NotFound` (a
file NodeId can no longer delete a directory).
- Copying a directory into its own subtree returns
`Bad_InvalidArgument`.
- **Locking:**
- An open file, or a directory containing one, cannot be deleted or
moved (`Bad_InvalidState`).
  - The check is atomic with opens.
- While a Delete or Move runs, read opens get `Bad_NotReadable` and
write opens `Bad_InvalidState`.
- **Open:**
- Reserved mode bits or EraseExisting without Write return
`Bad_InvalidArgument`.
  - Read+Write returns `Bad_NotSupported`.
  - Read while a writer is open returns `Bad_NotReadable`.
- **Client `FileSystemErrors`:** maps `Bad_NotReadable` to
`IOException`.
- **RuntimeNodeSet:** well-formed NodeSets with a stray `Model` element,
or two models in one file where one requires the other, now load.

### Server core, hosting and lifecycle
- **`SessionEstablishmentQueueLimit` > 0:**
CreateSession/ActivateSession now queue for a permit. The permit is
acquired before the request is registered, and a waiting handshake
releases its worker through the request-parking policy.
- **Node manager lifecycle:**
  - Add, reload and remove no longer wait for parked Publish requests.
- A Migrate reload racing with CreateMonitoredItems no longer blocks
later lifecycle operations.
  - Late items on retired or removed managers get `Bad_NodeIdUnknown`.
- **HistoryUpdate:** a batch mixing data and event details is bounded by
both limits.
- **Server stop/start:** stopping the server disposes the configuration
watcher and certificate subscription; starting recreates them.
- **Monitored-item queue factory:** a factory supplied by the caller or
the DI container is no longer disposed by the server.
- **Audit events:** each certificate validation error raises its own
AuditCertificate event. A failed OpenSecureChannel without a service
result is audited as failed.

## New public API (additive)
- `IQueuedSessionEstablishmentLimiter`
- `StandardServer.OwnsMonitoredItemQueueFactory` (protected virtual)
- `DefaultPkiRoot.Get` (Opc.Ua.Configuration)
- `TrustList.SetCertificateValidation`
- `NamespaceMetadataRegistry.Invalidate`
- `IApplicationConfigurationFileTargetProvider` and
`ApplicationConfigurationUpdatePlan`
- `GdsServerOptions.CertificateGroups` / `GdsCertificateGroupOptions`
- `InMemoryKeyCredentialRequestStore.AuthorizeRoles`
-
`DefaultManagedApplicationsNodeManager.ManagedApplicationsNamespaceUri`
- `AuthorizationServiceManager.RequestAccessTokenAsync(...,
IUserIdentity?, ...)`
- `AllowAnonymousWrite` on the file-system node manager and its factory
- `IFileSystemHost.TryBeginMutation` / `EndMutation`, replacing
`HasOpenHandles`

## Not fixed / known limitations
- **KeyCredential:** secret encryption with the client's PublicKey
(requests needing it are rejected).
- **CSR SAN restriction:** restricting subject / SAN values copied from
a CSR (CA policy).
- **Ticket signatures:** ticket signature verification (needs a
trusted-signer configuration).
- **FileType Read+Write open:** needs a read/write stream contract in
`IFileSystemProvider`.
- **Custom `IUserDatabase` implementations:** the disabled-user check
still scans all users per login. The built-in stores do a single lookup.
- **64-bit Delta precision:** limited by the calculator's double
arithmetic.

## Tests with changed expectations
Existing tests were updated where they asserted the old behaviour:
- File-system status codes
- Trust-list handle eviction
- `DiscardedMessageCount`
- Localized diagnostics bits
- Delta on unsigned sources
- SourceNode of fluent alarms
- ReferenceServer transfer permission test (now expects
`Bad_UserAccessDenied` notifications)
- `UserDeactivationShutdownReviewTests` (the revoked session is a
UserName login)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
2026-09-29 07:26:05 +02:00
Marc Schier 46fa7d364a Harden recovery, concurrency, and resource lifetimes across the OPC UA stack (#4516)
# Description

Bound managed-session recovery, preserve Publish workers and recovery
ownership, and address the client, server, transport, and certificate
audit findings and subsequent concurrency review. Also reduce the memory
retained by exhaustive session-test diagnostics.

## Recovery and Publish ownership

- Add `ManagedSessionOptions.ChannelReconnectTimeout` through direct
construction, the fluent builder, and DI. The automatic duration is
`max(3 * KeepAliveInterval, revised SessionTimeout, OperationTimeout)`,
sampled at cycle start. Positive overrides are supported;
`Timeout.InfiniteTimeSpan` explicitly opts out. Raw sessions retain
their unlimited default.
- Add `CreateReconnectBudget(TimeProvider)` as a required
`IReconnectParticipant` member, as agreed in review. Custom participants
implement it and may return null for no participant-specific bound.
- Enforce the earliest participant/caller deadline through transport
reconnect, activation/recreation, and subscription restoration. Late
callers can shorten an active cycle but cannot extend it.
- Cancel and unwind recovery, fence late responses, and release channel
recovery ownership before the existing `Faulted` event hands control to
the outer reconnect/failover policy. Preserve session recreate admission
through final Publish cleanup and keepalive suppression until shared
recovery is complete.
- Treat participant budget creation/evaluation failures, including
exceptions at the exact deadline, as terminal shared-recovery failures.
Notify participants before exposing `Faulted`, preserve the original
diagnostic, and never silently replace a finite budget with unlimited
recovery.
- Keep caller-supplied replacement channels, managed bindings, wrapper
event subscriptions, and recovery-owner identities consistent across
success, failure, and cancellation. Reject replacement during active
recovery and fence retired callbacks so they cannot clear newer
ownership or suppress later keepalive recovery.
- Retain eligible Publish workers through temporary
subscription-identifier clearing without retaining workers for
never-created or removed subscriptions. Preserve cancellation,
acknowledgement rollback, and drain-before-replacement ordering.
- Coordinate automatic subscription updates with session recovery:
cancel admitted updates, keep them paused across a failed-restoration
handoff, and retry only after explicit restoration completes. This
prevents competing CreateSubscription requests and updates against a
retiring session, while preserving manual recreation, transfer fallback,
and pending option changes.
- Exercise the real ManagedSession, V2 subscription engine, and channel
ready gate with scripted transports and an injected clock. Cover
transfer fallback, deadline handoff, late completions, and resumed
notification delivery.

## Audit and review corrections

- Correct certificate/trust-list transactions, change-pump lifetimes,
validation, peer revalidation, and reset/resource ownership.
- Harden node admission, attribute/range/dimension validation,
monitored-item sampling and lifecycle transitions, event fanout, and
server shutdown. Run lifecycle readiness and compensation outside shared
monitored-item admission, with stale-completion ownership checks.
- Close synchronous node-manager admission before teardown and retain
resources until admitted service, lifecycle, and asynchronous method
work returns. Dispose the monitored-item manager outside both locks,
reject late calls before they can reach it, and forward asynchronous
disposal through the adapter so the master awaits the same completion.
Preserve reentrant shutdown initiation, cancellation/failure unwinding,
and shared cleanup-failure reporting.
- Bound WSS pending-request retention using connection-local wire
handles while preserving caller-visible request handles and translating
Cancel targets. Safely ignore retired replies and drain admitted
send/close users before resource disposal.
- Clarify that the shared `ClientBase` caller-handle sequence is
distinct from the non-wrapping WSS wire allocator. Existing
exhaustion/reopen, late-reply, and Cancel-translation regressions verify
the connection-local contract; no allocator behavior was changed by this
clarification.
- Preserve virtual-node validation and resolver service errors instead
of converting them to cached misses. A mismatched NodeId reports
`BadNodeIdInvalid`; callback type mismatches and resolver service errors
keep their exact status. Per-item boundaries preserve unaffected reads,
writes, history operations, method calls, browse paths, and
monitored-item creation/restoration, including permission-validation
paths. Caller cancellation still propagates; stored-item validation
failures are logged without aborting later restores.
- Correct client file/role/state-machine/streaming APIs, node-cache
behavior, redundancy/failover ownership, and session
configuration/identity handling.
- Cancel each owned peer-discovery scope before disposing it, including
when the bounded wait wins a cancellation-delivery race. Keep late
results out of the endpoint cache and preserve single-flight lookup
ownership.
- Keep materialized alias Browse results synchronized with the live
store by default, preserving explicit startup-only opt-out. Apply
HistoryUpdate service results per value while retaining explicit
all-or-nothing provider APIs.
- Update the directly related feature documentation and add focused
positive, negative, concurrency, and ownership regressions.

## Latest review-feedback corrections

- Fence stale failed lease observations with a successful-confirmation
generation distinct from the revocation epoch. Snapshot it before each
store read, including failed-CAS revalidation, so an old failure cannot
revoke or reschedule a newer lease while fresh ownership loss still
revokes leadership. Preserve independent overlapping acquisitions,
expiry, disposal, and late-success protections.
- Isolate attributable WSS response-decoding errors to their request,
including retired handles. Keep admitted socket sends connection-owned
so caller timeout/cancellation cannot abort sibling requests; shutdown
still cancels and drains those sends.
- Restart keepalive and classic Publish replenishment after successful
session reuse. Retire V2 worker demand after intentional
deletion/disable without confusing that state with temporary recovery
resets.
- Browse virtual directories lazily across continuation pages without
the 1,024-entry snapshot cap. Preserve active-page cancellation, bounded
metadata retention, pushback, and exactly-once asynchronous cursor
cleanup.
- Apply certificate/CRL staging in last-operation order, preflight
required issuer storage before writes, select actual policy-compatible
RSA keys for None endpoints, frame certificate chains independently of
signature OIDs, and preserve admitted validation results during
rejected-writer shutdown.
- Preserve base asynchronous disposal when a legacy override omits its
base call; avoid double derived disposal in the adapter. Let genuinely
admitted nested work finish while rejecting stale captured contexts and
returning null from closed lookup APIs.
- Re-park recovered monitored items if AddNodes rolls back. Give event
compensation a fresh finite deadline, and preserve healthy
Browse/Translate siblings at every reference/path boundary while
retaining starting-node errors and caller cancellation.
- Give final reconnect notifications a live, bounded shutdown-linked
lifetime. Synchronize child state before parent lifecycle handlers
outside the parent transition lock.
- Document the accepted existing policies: direct reverse connections
are single-use without a ReverseConnectManager, and multi-node stream
capacity is shared rather than reserved per node.

The expanded readiness controls also exposed a real generation-handoff
race: an old source could finish draining after activation was deferred
but before readiness tasks were collected, causing the wanted
replacement to be omitted from the wait set. A deterministic test gates
that exact interval; the fix keeps the replacement in the readiness
wait. The original race passed 200 repetitions after the fix. A separate
control now awaits both producer readiness and iterator entry under the
same original deadline, rather than treating those independent signals
as equivalent. Temporary logging and repetition are removed.

## CI integration contracts

The History and Server CI failures exposed integration tests that still
asserted the behavior intentionally changed by the audit fixes. A
Windows WoT negative test raced its caller deadline against upstream
retries. A subsequent Ubuntu Client failure exposed a real
automatic-update versus explicit-restoration race:

- History insertion collisions now verify exact per-value statuses and
all persisted timestamps/values, including preservation of the existing
conflicting entry. Explicit atomic-provider rollback controls remain.
- Alias materialization tests wait for actual publication and verify the
added node plus forward/inverse `AliasFor` references, instead of racing
a startup-only snapshot expectation. Explicit refresh opt-out controls
remain.
- The unavailable-upstream WoT test uses an explicit finite retry policy
through existing DI configuration, preserving its original four-minute
guard and requiring a mapped-value service error before caller
cancellation. Production retry defaults remain unchanged.
- The Client fix retains the exact one-create and late-response
assertions. Three deterministic real-subscription/real-manager cases
cover paused creation, disposal while paused, and cancellation of an
admitted create followed by explicit restoration and a pending option
update. Both composed restoration-deadline cases also prove automatic
updates stay blocked at the outer handoff and resume after restoration.
- The merged-head net48 correction prevents lost peer-resolver
cancellation and distinguishes the harness's delayed initial `Connected`
event from actual outer recovery completion. A deterministic timer-order
test covers both cooperative and cancellation-ignoring resolvers,
cancellation before return, rejection of late cached results, and a
fresh subsequent lookup.
- The remaining CodeQL alert was a false content flow through
`ArrayOf.Count` into an integer-only trust-list summary. Projecting the
same count through `Span.Length` keeps cardinality distinct from
serialized contents without allocating, dropping diagnostics,
suppressing the rule, or dismissing the alert. Five log-contract cases
cover null/empty/nonempty results and mixed chain-capable/fallback
listeners, asserting the exact count, message, and structured
properties.
- Classic transfer acknowledges messages selected for asynchronous
Republish only after their responses arrive. The existing locked
replay-selection decision returns the immediate-acknowledgement subset
to Session, preserving the public transfer API, advertised availability,
and immediate acknowledgement of older gapped messages not selected for
replay. A callback changing `RepublishAfterTransfer` cannot change the
already-selected acknowledgement ownership.
- Transfer integration tests explicitly control acknowledged versus
retained origin messages. Exact assertions distinguish retained replay
from requested fresh initial values by sequence number, client handles,
values, status, and source timestamp. Atomic counters, observed
delivery/keepalive progress, and failure-safe session/file cleanup
replace timing assumptions and racy resets.
- Server lifecycle tests verify the documented independent five-second
compensation deadline rather than requiring a non-cancellable token.
They cancel the actual request, prove compensation and unrelated
monitored-item creation still proceed one tick before the deadline,
preserve the original failure and ownership assertions, and verify the
completed deadline is retired.
- Synchronous and asynchronous directory-browser tests require the exact
provider exception instead of an empty-directory success, then verify
the failed cursor is not enumerated again. These correct expectations
left behind by the intentional, documented provider-error propagation
change; production behavior is unchanged.

No tests were disabled, assertions loosened, coverage thresholds
lowered, or CI checks made optional. Existing platform exclusions and
Explicit debug variants remain.

## Related Issues

- Fixes #4514
- Fixes #4515
- Builds on merged #4503 and retains the #4508 publishing-drain
behavior.

## Validation

**Lease-election review correction
(`a13afa641182c70983e16bbcfebf507e666a45a5`):**

The correction is based on the existing upstream merge
`43079e2b851fe338a4082066f8d14abfdafb6e32`. Three deterministic
stale-verdict
cases fail on the original source and pass with separate confirmation
fencing.
Six new cases cover the initial foreign-owner verdict, failed-CAS
revalidation
in both invocation orders, and fresh ownership loss through both read
paths,
including revalidation begun after another successful confirmation.

| Target and configuration | Passed | Failed | Skipped |
| --- | ---: | ---: | ---: |
| net10.0 Debug | 120 | 0 | 0 |
| net48 Debug | 120 | 0 | 0 |

The selection is the full `Opc.Ua.Core.Tests.Redundancy` namespace,
including
all 38 `SharedStoreLeaseElectionTests` cases and the existing expiry,
clock
rollback, disposal, and overlapping-success regressions. New witnesses
are
`StaleForeignLeaseReadDoesNotRevokeNewerAcquisitionAsync`,
`StaleFailedRevalidationDoesNotRevokeNewerAcquisitionAsync`, and
`FreshForeignLeaseObservationRevokesLeadershipAsync`. They assert
resulting
leadership, exact transitions, independent progress, and the unchanged
expiry
boundary. Retaining the initial generation for the fallback read
independently
makes the fresh-loss-after-confirmation control fail; that mutation was
removed
before the final rebuilt runs.

The successful scoped command is
`dotnet test tests\Opc.Ua.Core.Tests\Opc.Ua.Core.Tests.csproj -c Debug
--no-restore --filter
"FullyQualifiedName~Opc.Ua.Core.Tests.Redundancy"`,
with `CustomTestTarget` and `-f` matching each row and that framework's
assets
restored. Both changed C# files pass formatting and analyzers through
informational severity on both frameworks. These are scoped results, not
a
full-solution test or measured coverage-delta claim. CI monitoring is
paused
for this feedback-only operation; no current-head CI success is claimed.

**Latest CI contract correction
(`1cd1f2047bb5b50c9bf300b1ff710b0b2e935a29`):**

All four failing Server shard 23 jobs in
[run
36120946740](https://github.com/OPCFoundation/UA-.NETStandard/actions/runs/36120946740)
reported the same six cases. Two local replays reproduced all six
failures.
The source changes and documentation from `cd43b831a` establish both
intentional
contracts: independent bounded event compensation and surfaced provider
errors.
Only the two test files are corrected; production code and CI policy are
unchanged.

| Target and configuration | Passed | Failed | Skipped |
| --- | ---: | ---: | ---: |
| net48 Debug | 113 | 0 | 0 |
| net10.0 Release, CI Coverlet settings | 113 | 0 | 0 |

The selection contains `MonitoredItemManagerLifecycleTests`,
`DirectoryObjectStateTests`, `DirectoryBrowserBoundedEnumerationTests`,
and

`EventCompensationReadinessHasFiniteDeadlineWithInfiniteSourceTimeoutAsync`.
Both changed files pass formatting and analyzers through informational
severity
on both frameworks. Independent mutations restoring a non-cancellable
compensation token and swallowing provider errors fail all four
lifecycle
cases and both browser cases, respectively. Both mutations were removed
before
the final passing runs and commit.

The scoped command is `dotnet test
tests\Opc.Ua.Server.Tests\Opc.Ua.Server.Tests.csproj`
with `CustomTestTarget` and `-f` set to the selected framework,
`--no-restore`, and
`--filter
"FullyQualifiedName~MonitoredItemManagerLifecycleTests|FullyQualifiedName~DirectoryObjectStateTests|FullyQualifiedName~DirectoryBrowserBoundedEnumerationTests|FullyQualifiedName~EventCompensationReadinessHasFiniteDeadlineWithInfiniteSourceTimeoutAsync"`.
The modern run additionally uses `-c Release /p:CollectCoverage=true
--collect "XPlat Code Coverage" --settings
tests\coverlet.runsettings.xml`.
These are scoped results, not a full-solution test or measured
coverage-delta claim.
Hosted checks for that commit were pending at publication. The fail-fast
CI
watch was stopped when the requested operation switched to review
feedback;
no current-head CI success is claimed.

**Earlier master merge (`8b15ea6ef9fc2214ac8ec886f373bb3846dd6d6f`, base
`b4136d8e9bab0df680f41d9ef985f519160534b1`):**

The `TcpListenerChannel` conflict preserves both lifetime
responsibilities:
disposal clears the retained peer-certificate chain and unregisters the
quota-scoped message-assembly scheduler. Both fields and all upstream
deadline
handling remain intact. The only additional manual source adjustment
adds the
parentheses required by the existing analyzer around the session-count
fallback.

Master advanced during validation. The initial transport merge
`80303c434ce813cf75aa7fe54a6a32fe2aeafc30` was retained, and the newer
base was
merged normally in `8b15ea6ef9fc2214ac8ec886f373bb3846dd6d6f`, without
rewriting
history. The additional recovery, fluent-pipeline, and test-framework
overlaps
were inspected; the branch's cancellation, validation-error, and
acknowledgement
ownership fixes remain alongside the upstream changes.

Full `UA.slnx` builds passed on net10.0 and net48 with **0 warnings and
0 errors**.
The final scoped tests rebuilt against the committed tree
`2074f8efcb61d8d9c6106e7d6f76ee941940e358`:

| Target | Passed | Failed | Skipped |
| --- | ---: | ---: | ---: |
| net10.0 | 2,653 | 0 | 0 |
| net48 | 2,529 | 0 | 7 |

The net48 skips are existing platform exclusions: six RSA_DH_AesGcm
nonce cases
and one ClientWebSocket certificate-validation case requiring .NET 7 or
later.
The selection covers transport cleanup, reassembly
budgets/deadlines/admission,
peer-chain ownership, server session binding, fluent lifecycles and
source
generation, reconnect and keepalive, transfer acknowledgements, Publish
queues,
and JSON encoding. Modern-.NET WSS transport and real-server integration
cases
also pass. The resolved file passed solution-relative formatting and
analyzer
verification through informational severity on both frameworks.

These are scoped test results, not unfiltered full-suite or
measured-coverage
claims. Hosted CI was not monitored or repaired as part of this
merge-only
operation.

Selected local results below are overlapping validation runs, not
distinct-test totals.

**Earlier review-feedback batch
(`cd43b831a8f11de3f7d65c3681712a61e3c669a5`):**
The final net10.0 scoped selection passed **471 tests, with no failures
or skips**.
The final net48 solution-root selection passed **439 tests, with no
failures and
one unchanged platform skip**
(`ValidateServerCertificateFallsBackToTlsPolicyErrors`,
which requires newer ClientWebSocket certificate-validation support).
Both full nonincremental solution builds completed with **0 warnings and
0 errors**,
and all **40 changed C# files** passed informational-level
formatting/analyzer
verification. Both frameworks validated the identical final tracked
diff.
The focused matrix covers every one of the 20 current review threads,
including
real mid-frame WSS cancellation, stale admission contexts, directory
continuation
ownership, multi-element Browse/Translate failures, and the readiness
drain race.
The net10.0 solution-root test command has a separate pre-existing
runner conflict:
three unrelated AOT projects reject the VSTest target under
Microsoft.Testing.Platform
2.4.0 and SDK 10. Per-project net10.0 results are recorded separately;
no runner
migration, test exclusion, assertion relaxation, or CI-policy change is
included.
These are bounded selections, not unfiltered full-suite or measured
coverage claims.
At publication of `cd43b831a`, hosted CI was not green: the
`OPCFoundation.UA-.NETStandard` check reported `ACTION_REQUIRED`,
AppVeyor reported
`FAILURE`, and the two signed-build jobs were in progress. No CI jobs
were rerun,
cancelled, approved, or repaired as part of that feedback-only
operation.

**Classic transfer correction
(`f425376fca045794122e19aaf9cafebc4a717d91`):**
The preceding head's
[macOS net10.0 shard
25/30](https://github.com/OPCFoundation/UA-.NETStandard/actions/runs/35980326299/job/107570512458)
failed
`TransferSubscriptionTest(DisconnectedRepublish).TransferSubscriptionAsync(True,False)`
at the static-node count assertion: expected 10, received 20. The trace
contains a successful,
explicitly requested republish of retained sequence 1 and a fresh
initial-value batch at sequence 3,
not duplicate dispatch of one response.

Controlled lost origin acknowledgements reproduced that incorrect test
expectation on both the
preceding PR head and exact master base
`a2539cb53dd1666cef856f33812d7a8830d68909`.
The maintainer explicitly authorized correcting this existing issue in
the PR. Retained replay
and requested initial values are independent, as specified by
[OPC UA Part 4,
TransferSubscriptions](https://reference.opcfoundation.org/specs/OPC-10000-4/5.14.7).
The reason that the original hosted run retained its particular origin
message remains unproved.

The expanded full-suite run then exposed a **real production race**, not
just a count assertion:
Session queued acknowledgements for all transferred available messages
before the asynchronous
Republish responses arrived. Publish could delete those messages first,
causing
`BadMessageNotAvailable`. A gated real-Session/classic-engine regression
failed both replay-enabled
cases on the original implementation while both no-replay controls
passed. The ownership fix
passes all 24 combinations of empty/consecutive/unsorted-gapped queues,
replay preference,
sequential delivery, and a reentrant preference change.

All 40 normal real-server transfer cases pass on both frameworks.
Independent mutations
suppressing actual replay and duplicating observed sequence records each
fail the intended
assertion; both mutations were removed. The full classic suite passes on
both frameworks.
Hosted CI was pending when that correction was published; the earlier
failed hosted job was not
rerun for a lucky pass.

**Local net48 caveat:** the full Client run timed out in the
pre-existing fake-clock test
`ReconnectAsyncSwapsFaultedLeaseEntryAsync`, which does not exercise
subscription transfer.
Its unchanged isolated replay passed, but that does not resolve the
full-suite timeout.
No unrelated code or assertions were changed, and a clean full Client
net48 run is not claimed.

| Scope | net10.0 | net48 |
| --- | --- | --- |
| Full Client.Tests after transfer acknowledgement correction | 2,549
passed | 2,552 passed, 1 timeout failure noted above, 1 existing
platform skip |
| Full classic-subscription project after transfer correction | 57
passed, including all 40 normal transfer cases | 57 passed, including
all 40 normal transfer cases |
| Gated transferred-message acknowledgement ownership | 24 passed,
included above | 24 passed, included above |
| Saved-session consumer of the shared subscription helper | 40 passed |
16 passed, 24 existing unsupported-security-policy skips |
| Audit regression matrix | 2,339 passed | 1,934 passed, 34 existing
skips |
| Full Client.Tests after review follow-ups | 2,520 passed | Focused
selections only |
| Full Client.Tests after CI recovery correction | 2,523 passed, CI
coverage collector | 2,527 passed, 1 existing platform skip |
| Latest merged-head recovery/redundancy selection | 139 passed | 139
passed |
| Full Client.Tests after merged-head net48 correction | Focused
selection above | 2,529 passed, 1 existing platform skip |
| Lifecycle and actual-dimension regressions | 146 passed | 146 passed |
| Focused recovery follow-ups | 7 passed | 7 passed |
| WSS-related fixtures | 93 passed | Not applicable |
| CI History integration corrections | 28 passed | 28 passed |
| CI alias, dispatcher, and explicit-atomic controls | 63 passed | 63
passed |
| Full WoT sample project with CI coverage collector | 29 passed | Not
applicable |
| Trust-list effects and count-only summary contract | 22 passed | 22
passed |
| Virtual-node feedback, node-manager, dispatcher, and lifecycle
selections | 661 passed, 63 existing not-executed cases; all 48
virtual-node cases passed | 661 passed, 63 existing not-executed cases;
all 48 virtual-node cases passed |
| WSS wire-handle exhaustion, late replies, and Cancel translation | 9
passed | Not applicable |
| Synchronous node-manager disposal and related service/lifecycle suites
| 1,037 passed, 64 not-executed cases from existing fixture assumptions;
all 93 sampling/disposal cases passed | 1,037 passed, 64 not-executed
cases from existing fixture assumptions; all 93 sampling/disposal cases
passed |

- Full solution builds passed on net10.0 and net48 during the audit
work. The subsequent full non-incremental net10.0 build also completed
with zero warnings/errors.
- Modified source/test formatting and analyzer checks passed through
informational severity.
- Original composed recovery regressions passed repeated runs on both
frameworks. Independent mutations removing Publish cancellation,
bypassing the recreate drain call, or ignoring ready-gate cancellation
each failed the intended assertion; all mutations were restored before
passing runs.
- The latest recovery correction passed 100 executions of each original
restoration-deadline scenario with unchanged assertions. Restoring
premature update admission independently made both strengthened handoff
cases fail; the correct retention behavior was restored afterward.
- Startup-event and cancellation-delivery timing probes reproduced the
subsequent net48 failures, then passed 100 executions of each of the
three scenarios with the fixes. All timing probes and repetition were
removed. The permanent timeout-order regression also went RED on the
original cancellation cleanup without sleeps or scheduling
amplification.
- Final post-format recovery/subscription/engine checks passed all 151
selected cases on net10.0. The first local full net48 attempt aborted in
`clr.dll` with native access violation `0xc0000005`; an
unchanged-assembly full diagnostic rerun passed as recorded above. That
native host crash has not been attributed or claimed fixed.
- A minimal replay with the same CodeQL CLI and query-pack versions
reproduced the custom-count alert and confirmed that the standard
span-length projection is clean while direct sensitive-value and
raw-identifier logging controls remain flagged. The source was already
logging only a count; no identifier or certificate disclosure was
established at the reported location.
- The virtual-node feedback regressions first reproduced five
error-preservation/cache failures; expanded service-dispatch cases
exposed two additional whole-batch failures before the
operation-boundary fixes. The final selections pass on both frameworks.
Genuine misses remain cached, successful results remain reusable, failed
validation allows same-cache retry, and request cancellation still stops
the batch.
- Three deterministic synchronous-manager disposal regressions
reproduced early resource release and lifecycle calls reaching a manager
during disposal. The fix passes direct and adapted calls, a
sampling-worker join after the last operation exits, reentrant shutdown,
cancellation and failure paths, repeated disposal, and exact rejection
across 39 service/lifecycle entry points both during drain and after
cleanup. The original outside-node-lock disposal regression remains and
now requires the worker to observe closed admission.
- Prior-head CI on `c985f8bded77a60449d9cd381c8a004d8590ccf6` completed
with **168 passing checks, one expected release-package-publication
skip, and no failures or pending checks**. All test shards, signed
builds, container builds, the coverage check, and the CodeQL PR check
passed. Hosted CodeQL analysis `1829262912` completed successfully and
marks count-flow alert 385 fixed. This is evidence for that head, not a
claim that subsequent review follow-ups have completed hosted CI.

### Session-test diagnostic memory

Complete browse listings are streamed to unique NUnit attachments rather
than retained in inline NUnit/VSTest output. Detached regression-test
results are cleaned up without deleting runner-collected attachments.

- Two covered session-suite runs each completed with 782 passed and 379
existing skips. Peak working set fell from 4.86 GiB to 2.44-2.78 GiB.
- TRX output shrank from 303.1 MiB to approximately 40.7 MiB, retaining
all 46 complete browse attachments.
- Seven output regressions cover exact content, empty/single/large
listings, disabled/enabled output, bounded inline summaries, and unique
filenames.

The separate Azure build-18452 VM deprovisioning cause remains unproved
without provider logs. The memory measurements do not establish its
cause.

Unfiltered local `UA.slnx` tests, including the long stress/soak suites,
have not been run on both frameworks. A local coverage delta was not
collected; builds and focused tests are not substitutes for those
claims.

## Checklist

- [ ] 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.
- [ ] 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.
- [ ] I ran **all** tests locally using the **UA.slnx** solution against
at least .net **framework** and .net **10**, and all passed.
- [ ] All checks on the latest review-follow-up head have completed
successfully; prior-head CI passed as recorded above.
- [x] I have addressed **all** PR feedback received.

Tests have been added and pass as recorded above; the hosted coverage
check passed on the prior head identified above. The combined
tests/coverage-increase checkbox remains open because no local coverage
delta was measured.

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 68f26810-22b8-476f-abcd-0a8c82d6e208
2026-09-25 14:59:34 +00:00
romanett 556c9cb797 Add an async iteration seam to NodeBrowser (#4450)
# Description

`NodeBrowser` was synchronous end to end, so a node manager whose browse
result depends on I/O had nowhere to `await`. The aggregation server
sample is the concrete case: its browser has to browse the aggregated
server, and the only way to write it was `Next() =>
NextAsync().GetAwaiter().GetResult()`, which holds a request worker for
the full remote round trip on every browse.

This is option (1) from the issue, the small non-breaking step:

- `INodeBrowser` and `NodeBrowser` gain `ValueTask<IReference?>
NextAsync(CancellationToken cancellationToken = default)`. The default
completes synchronously with the result of `Next()`, so every existing
browser that only overrides `Next()` keeps working unchanged (the
samples' `MemoryBufferBrowser` and the migration-analyzer test snippets
compile untouched).
- `AsyncCustomNodeManager.BrowseAsync` and `TranslateBrowsePathAsync`
iterate browsers through `NextAsync` with the request's cancellation
token. The loop bodies already awaited; only the iteration could not.
- `DirectoryBrowser` was the one browser the stack ships that blocked on
async I/O. It now awaits the file-system provider enumeration in
`NextAsync` and keeps `Next()` as the bridge for the remaining
synchronous consumers (`UANodeSetHelpers` export, `CustomNodeManager2`).
Cancellation now propagates instead of being reported as an empty
directory.
- The synchronous paths (`CustomNodeManager2`, `CoreNodeManager`
diagnostics, nodeset export) are unchanged on purpose; they have no
place to await.

**Not done, by design.** Browser creation stays synchronous.
`OnCreateBrowser` runs under the node's browse lock, so the documented
contract is that a browser fetches lazily on its first `NextAsync`. The
issue itself notes the async creation seam is not needed for the
aggregation case. `IAsyncEnumerable` (option 3) is not attempted.

**Compatibility note.** A type that implements `INodeBrowser` directly
without deriving from `NodeBrowser` has to add the member. Nothing in
this repo or the samples does that; derived browsers are unaffected.

**Docs** updated in `NodeManagers.md`, `AsyncServerSupport.md`,
`MigrationGuide.md` and `migrate/2.0.x/node-states.md`, with a was/now
example for a browser that previously bridged sync-over-async.

**Tests**
- `NodeBrowserTests` (new): default wrapper completes synchronously and
yields the same sequence as `Next()`, push-back through `NextAsync`, a
`Next`-only override observed through `NextAsync`, an awaited
`NextAsync` override with cancellation.
- `AsyncCustomNodeManagerTests`: a browser whose `Next()` throws is
driven entirely through `NextAsync` by browse, by the continuation-point
round trip (push-back on the async path), and by translate-path.
- `DirectoryObjectStateTests`: the async path of the directory browser,
including the throwing provider and cancellation.

Verified locally: `Opc.Ua.Server` builds on net10.0 and net48 with 0
errors; the browser-related server suites (1342 tests) and the new unit
tests pass on net10.0; `dotnet format whitespace --verify-no-changes` is
clean on the changed files.

## Related Issues

- Fixes #4415

## 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.
- [ ] I ran **all** tests locally using the **UA.slnx** solution against
at least .net **framework** and .net **10**, and all passed.
- [ ] I fixed **all** failing and flaky tests in the CI pipelines and
**all** CodeQL warnings.
- [ ] I have addressed **all** PR feedback received.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com>
2026-09-08 19:56:53 +02:00
Marc Schier 91d3305b1c Scope FileType handles to Sessions (OPC 10000-5) (#4048)
# Description

This focused draft extracts the FileType handle ownership fix from
#4021. It contains only the server FileSystem handle implementation,
focused tests, and FileSystem client documentation.

## Failure

`FileHandle` issued predictable per-file identifiers without recording
the owning Session. A different Session that obtained a handle could
read, write, seek, or close the stream, and open streams survived
Session closure.

## Fix

- Generate non-zero opaque handles and bind every open stream to the
Session that called `Open`.
- Require a valid Session for `FileType.Open`, `CreateFile` when it
requests an open handle, and all subsequent handle operations.
- Reject a handle presented by another Session.
- Close only the departing Session's handles from
`FileSystemNodeManager.SessionClosingAsync`.
- Document the Session ownership and lifetime.

OPC 10000-5 Section 6.2.5.2, Table 27 states that a `fileHandle` is
valid only for the Session used to call `Open` and that the Server shall
automatically close the file when that Session closes.

## Tests

- `dotnet test tests\Opc.Ua.Server.Tests\Opc.Ua.Server.Tests.csproj -f
net10.0 --filter
"FullyQualifiedName~FileHandleTests|FullyQualifiedName~FileObjectStateTests|FullyQualifiedName~DirectoryObjectStateTests"
--no-restore`: 71 passed.
- `dotnet test tests\Opc.Ua.Server.Tests\Opc.Ua.Server.Tests.csproj -f
net48 --filter
"FullyQualifiedName~FileHandleTests|FullyQualifiedName~FileObjectStateTests|FullyQualifiedName~DirectoryObjectStateTests"
--no-restore`: 71 passed.

Both builds emitted the same existing CA1873 warnings in unchanged
`Opc.Ua.Client` files; the changed files produced no warnings.

## Related Issues

- Focused split from #4021 (closed umbrella draft); no separate issue.

## Checklist

- [ ] 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.
- [ ] I ran **all** tests locally using the **UA.slnx** solution against
at least .net **framework** and .net **10**, and all passed.
- [ ] I fixed **all** failing and flaky tests in the CI pipelines and
**all** CodeQL warnings.
- [ ] I have addressed **all** PR feedback received.

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
2026-07-22 16:50:56 +02:00
Marc Schier 7cec2d614d Move repository files to the consolidated layout 2026-07-16 06:25:54 +02:00