CTT follow-up: monitored items, alarms, codecs, history, and model validation (#4002)

# Description

Follow-up to #3978 based on the latest OPC UA CTT aggregate, matrix,
Historical Access, Attribute, and Node Management runs.

## Aggregate run 16

- Ignore synthetic `BadBoundNotFound` raw-bound markers when feeding
aggregate calculators.
- Add direct and live historian regression coverage.

## Multi-dimensional Variant matrices

- Fix `Variant.Copy()` so rank-2 Variant matrices preserve their payload
and dimensions.
- Enforce valid Variant matrix dimensions consistently across Binary,
JSON, XML stream, and XML parser codecs.
- Encoders return `BadEncodingError`; decoders return `BadDecodingError`
for malformed matrix dimensions.
- Add cross-codec valid/null/empty/malformed tests and a batched
ReferenceServer Read regression.
- Correct the previous CTT issue attribution: the invalid
`Scalar_Static_Arrays2D_Variant` server encoding poisoned the batched
CTT Read.

## Node Management AddNodes

- Return `BadNodeIdRejected` for unsupported requested-NodeId
namespaces.
- Validate hierarchical ReferenceType source/target NodeClass
constraints.
- Document run-18 confirmation that all remaining 15 AddNodes errors are
CTT project/script configuration issues.

## Historical Access and Attribute Services run 18

- Reject whitespace in `NumericRange` syntax with
`BadIndexRangeInvalid`.
- Add HistoryRead tests for operation-level invalid syntax and
per-DataValue `BadIndexRangeNoData`.
- Document CTT defects:
- `012.js` expects `BadIndexRangeNoData` at the operation level instead
of on returned DataValues;
  - `Err-012.js` uses a non-historizing node for an access-denied test;
- generic Attribute array helpers omit NodeId[] and StatusCode[]
conversion paths.

## Base Information model validation run 19

- Run the CTT main session as `sysadmin` over Basic256Sha256
SignAndEncrypt so SecurityAdmin RolePermissions and EncryptionRequired
restrictions are both satisfied without weakening the server model.
- Preserve predefined well-known NodeIds while making generated dynamic
type and optional-child factories allocate compatible per-instance
NodeIds, remap internal references, and update references from the
owning subtree.
- Materialize dynamic RoleType properties through generated helpers and
keep role-child string NodeIds disjoint from numeric RoleManager root
IDs.
- Add net48/net10 regressions for generator output, NodeId
allocation/reference remapping, DI mandatory children, dynamic roles,
and low-privilege versus SecurityAdmin Browse visibility.
- Document CTT defects for permission-unaware mandatory-child
validation, the UA 1.04 reference model used against a UA 1.05 server,
stale ServerDiagnostics cache, and the `ConformanceUnits` scalar/array
mismatch.
## Related Issues

- Follow-up to #3960 and #3978.

## Checklist

- [x] I have signed the CLA and read the CONTRIBUTING document.
- [x] Tests prove the fixes and improve coverage.
- [x] Required CTT documentation is updated.
- [x] Focused builds/tests introduce no warnings.
- [x] Affected tests pass on .NET Framework and .NET 10.
- [ ] CI and CodeQL are green.
- [ ] All PR feedback is addressed.



## Latest CTT full run and A&C run 20

- Fix Monitor Value Change V2 `036.js`: an ambiguous
`DataValue(StatusCode)` call encoded `BadIndexRangeNoData` as a Good
value.
- Prove all 19 configured matrix monitored items notify when the
selected value actually changes; document the independent `042.js`
script defects.
- Rebase dynamic `CertificateExpired` / `TrustListOutOfDate` alarm roots
and descendants, restore standard type declarations and ModellingRules,
and expose the cross-node-manager references.
- Deliver method-triggered events to every authorized Session, fixing
the two-Session Confirm scenario.
- Preserve locale-only `LocalizedText` values consistently across
Binary, JSON, and XML and align Acknowledge/Confirm comment behavior and
tests.
- Document the remaining proven CTT defects for TransactionDiagnostics,
SemanticChange, History `013`, PolicyId scope, A&C, durable
subscriptions, and Subscription Minimum events.

## Base synchronization

Merged `master` through `007cfaf90` (`#4010`, repository layout
consolidation) and retained the matrix regression tests at their new
`tests/` locations.

## Latest validation

- Focused merged-tree tests pass on net10 and net48.
- `Opc.Ua.Server` and `Quickstarts.Servers` Release builds complete with
0 warnings and 0 errors on net10 and net48.
- The existing
`DisableEnableViaTypeAndInstanceMethodNoEventsDuringDisabledAsync`
timing test took its documented inconclusive timeout path after the
layout merge; no test failure was reported.

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: Copilot <198982749+Copilot@users.noreply.github.com>
Co-authored-by: romanett <romanett98@gmail.com>

Author: 4 people

docs/migrate/2.0.x/types.md

@@ -266,7 +266,7 @@ To migrate, perform the following general replacements in your code:
 6. **Decoders use the sentinel.** `IDecoder.ReadDataValue` (Binary, Xml, Json) returns `DataValue.Null` when the field is absent (or, for the binary encoder, when the encoding byte is `0`), allowing callers to distinguish "missing" from "present but empty".
 7. **Prefer `in DataValue` for synchronous method parameters.** The struct is large (~64 bytes after the IsNull sentinel) and copying it on every call is wasteful. The server `IDataChangeMonitoredItem.QueueValue(in DataValue, ...)` API has been updated accordingly. Async methods cannot use `in`/`ref` parameters, so leave those by-value.
 8. **`object? GetValue(Type)` and `T? GetValueOrDefault<T>()` are now `[Obsolete]`.** Use `WrappedValue.TryGetValue<T>(out T value)` or `WrappedValue.TryGetStructure<T>(out T value)` for type-safe extraction without throwing. `GetValue<T>(T defaultValue)` remains supported.
-9. **`DataValue.FromStatusCode(StatusCode)` and `FromStatusCode(StatusCode, DateTimeUtc serverTimestamp)`** are the preferred way to construct a `DataValue` that conveys only a status. The `DataValue(StatusCode)` and `DataValue(StatusCode, DateTimeUtc)` constructors are `[Obsolete]` because they conflict with overload resolution against the numeric `Variant` types (`uint`/`int`/`StatusCode` all implicitly convert in different directions).
+9. **`DataValue.FromStatusCode(StatusCode)` and `FromStatusCode(StatusCode, DateTimeUtc serverTimestamp)`** are the preferred way to construct a `DataValue` that conveys only a status. The `DataValue(StatusCode)` and `DataValue(StatusCode, DateTimeUtc)` constructors are `[Obsolete]` because they conflict with overload resolution against the numeric `Variant` types (`uint`/`int`/`StatusCode` all implicitly convert in different directions). Recompile existing `new DataValue(statusCode)` calls and replace the resulting obsolete warnings with `DataValue.FromStatusCode(statusCode)`; this also avoids relying on historical compiler overload selection that could encode the StatusCode as a Good Variant value.
 
 **Change code as follows:**
 
@@ -404,4 +404,3 @@ No changes are required, however there can be subtle bugs exposed, e.g.:
 - Related: [encoders.md](encoders.md), [source-generation.md](source-generation.md), [node-states.md](node-states.md).
 - [2.0 migration index](README.md) — analyzer quick-start + symptom → sub-doc table.
 - [Migration Guide](../../MigrationGuide.md) — landing page across versions.
-

plans/ctt-issues.md

@@ -1205,7 +1205,7 @@ public async Task<ResultSet<DataValue>> ReadAllValuesAsync(
                             catch (ServiceResultException sre)
                             {
                                 m_logger.Error(sre);
-                                values.Add(new DataValue(sre.StatusCode));
+                                values.Add(DataValue.FromStatusCode(sre.StatusCode));
                                 errors.Add(sre.Result);
                             }
                         }

samples/ConsoleReferenceClient/ClientSamples.cs

@@ -370,7 +370,7 @@ public void ValueChanged(ISystemContext context)
 
             if (ServiceResult.IsBad(error))
             {
-                value = new DataValue(error.StatusCode);
+                value = DataValue.FromStatusCode(error.StatusCode);
             }
 
             value = value.WithServerTimestamp(DateTimeUtc.Now);

samples/Quickstarts.Servers/ReferenceServer/ReferenceNodeManager.cs

@@ -487,7 +487,8 @@ private static bool CanSetComment(LocalizedText comment)
             // Per OPC UA Part 9, a Null comment (no translation and empty/absent
             // text) passed to Acknowledge or Confirm must not overwrite the
             // Condition's existing Comment.
-            return !comment.IsNullOrEmpty;
+            return !comment.IsNullOrEmpty ||
+                !string.IsNullOrEmpty(comment.Locale);
         }
 
         private static LocalizedText NormalizeMethodComment(LocalizedText comment)

samples/Quickstarts.Servers/SampleNodeManager/DataChangeMonitoredItem.cs

@@ -394,10 +394,13 @@ private static void FinaliseChild(
             child.SymbolicName = browseName.Name ?? string.Empty;
             child.BrowseName = browseName;
             child.DisplayName = new LocalizedText(browseName.Name);
-            child.NodeId = context.NodeIdFactory.New(context, child);
+            NodeId previousNodeId = context.AssignInstanceNodeId(child);
             child.ReferenceTypeId = Types.ReferenceTypeIds.HasComponent;
             child.ModellingRuleId = NodeId.Null;
-            context.AssignInstanceChildNodeIds(child);
+            context.AssignInstanceChildNodeIds(
+                child,
+                previousNodeId,
+                child.Parent ?? child);
         }
 
         private static async ValueTask<ServiceResult> InvokePrepareAsync(

samples/UAReferenceServer.ctt.xml

@@ -115,7 +115,8 @@ public bool QueueRawValue(DataValue value)
             }
 
             // ignore placeholders in the stream.
-            if (value.StatusCode == StatusCodes.BadNoData)
+            if (value.StatusCode == StatusCodes.BadNoData ||
+                value.StatusCode == StatusCodes.BadBoundNotFound)
             {
                 return true;
             }
@@ -525,6 +526,11 @@ protected class TimeSlice
             /// </summary>
             public LinkedListNode<DataValue> EarlyBound { get; set; } = null!;
 
+            /// <summary>
+            /// The latest non-Bad value before the slice.
+            /// </summary>
+            public LinkedListNode<DataValue> NonBadEarlyBound { get; set; } = null!;
+
             /// <summary>
             /// The second early bound for the slice (always earlier than the first).
             /// </summary>
@@ -642,6 +648,11 @@ protected bool UpdateSlice(TimeSlice slice)
                     // check if before the beginning of the slice.
                     if (CompareTimestamps(slice.StartTime, ii) >= 0)
                     {
+                        if (StatusCode.IsNotBad(ii.Value.StatusCode))
+                        {
+                            slice.NonBadEarlyBound = ii;
+                        }
+
                         if (IsGood(ii.Value))
                         {
                             slice.SecondEarlyBound = slice.EarlyBound;
@@ -678,6 +689,11 @@ protected bool UpdateSlice(TimeSlice slice)
                     // check if before the beginning of the slice.
                     if (CompareTimestamps(slice.StartTime, ii) > 0)
                     {
+                        if (StatusCode.IsNotBad(ii.Value.StatusCode))
+                        {
+                            slice.NonBadEarlyBound = ii;
+                        }
+
                         if (IsGood(ii.Value))
                         {
                             slice.SecondEarlyBound = slice.EarlyBound;

src/Opc.Ua.Core.Types/State/AcknowledgeableConditionState.cs

@@ -234,46 +234,30 @@ protected DataValue ComputeNumberOfTransitions(TimeSlice slice)
                 return GetNoDataValue(slice);
             }
 
-            // determine whether a transition occurs at the StartTime
-            double lastValue = double.NaN;
-
-            if (slice.EarlyBound != null && StatusCode.IsGood(slice.EarlyBound.Value.StatusCode))
-            {
-                try
-                {
-                    lastValue = CastToDouble(slice.EarlyBound.Value);
-                }
-                catch (Exception)
-                {
-                    lastValue = double.NaN;
-                }
-            }
+            // The first non-Bad value is a transition when no previous non-Bad value exists.
+            LinkedListNode<DataValue>? previousValue = slice.NonBadEarlyBound;
+            bool hasLastValue = previousValue != null;
+            Variant lastValue = previousValue != null
+                ? previousValue.Value.WrappedValue
+                : Variant.Null;
 
             // count the transitions.
             int count = 0;
 
             for (int ii = 0; ii < values.Count; ii++)
             {
-                if (!IsGood(values[ii]))
-                {
-                    continue;
-                }
-
-                double nextValue;
-                try
-                {
-                    nextValue = CastToDouble(values[ii]);
-                }
-                catch (Exception)
+                if (StatusCode.IsBad(values[ii].StatusCode))
                 {
                     continue;
                 }
 
-                if (!double.IsNaN(lastValue) && lastValue != nextValue)
+                Variant nextValue = values[ii].WrappedValue;
+                if (!hasLastValue || lastValue != nextValue)
                 {
                     count++;
                 }
 
+                hasLastValue = true;
                 lastValue = nextValue;
             }