fix(chat): avoid session-switch crashes without clipping Markdown lists

docs/WINDOWS_NODE_TESTING.md

@@ -28,6 +28,31 @@ For changes touching tray UX, Settings, onboarding, chat/canvas, Command Center,
 
 Short version: run required tests, collect a closeout proof pass with `.\run-app-local.ps1 -Isolated` when UI is involved, use computer-use or developer-provided screenshots/output for the active changed UI state, prove MCP with `winnode` or raw JSON-RPC, prove gateway paths when available, and include current-head concrete output under `## Real behavior proof`. Mid-development computer-use/MCP/rubber-duck validation is fine when explicitly requested or needed to unblock work.
 
+### Reactor preview.12 compatibility proof
+
+Both Reactor packages are temporarily pinned to `0.1.0-preview.12` while
+[microsoft/microsoft-ui-xaml#11865](https://github.com/microsoft/microsoft-ui-xaml/issues/11865)
+awaits a released and validated fix. `ReactorChatTimeline.BuildSafeMarkdown`
+uses `MarkdownOptions.ListItem` to replace the default horizontal list row with
+an Auto-marker/Star-content Grid, preserving the existing marker, content and
+spacing. This locally supplies the wrapping fix from
+[microsoft/microsoft-ui-reactor#1197](https://github.com/microsoft/microsoft-ui-reactor/pull/1197)
+without adopting preview.13's row eviction behavior.
+
+Run `ReactorMarkdownListProofTests` in `OpenClaw.Tray.UITests` on the host's
+native architecture. These mounted tests check ordered/unordered wrapping at
+240 DIPs, reflow at 600 DIPs, and nested/loose list content and formatting.
+Keep the existing table and disposal proof in the focused run.
+
+Before release or removing the pin, also exercise repeated session switching
+while a bring-into-view request is pending, using 240 mixed-height messages.
+Verify that message 240 is actually visible, not just that the current scroll
+extent was reached. Verify streaming tail-follow and arrivals while scrolled
+up. Do not substitute extent-only scrolling: the alternative workaround
+stopped near message 233 in the reported scenario.
+[Tracking issue #1424](https://github.com/openclaw/openclaw-windows-node/issues/1424)
+owns the package upgrade and removal gates.
+
 ### New command MCP contract
 
 Every new Windows node call must be exposed through local MCP and `winnode`: register the capability, update `McpToolBridge.CommandDescriptions`, update `.agents/skills/winnode/SKILL.md`, add focused tests, and prove discovery/invocation with `winnode` or raw MCP JSON-RPC.

src/OpenClaw.Tray.WinUI/Chat/ReactorChatTimeline.cs

@@ -550,6 +550,7 @@ internal static Element BuildSafeMarkdown(string? text)
         var options = new MarkdownOptions
         {
             ParserFlags = MarkdownParserFlags.Tables | MarkdownParserFlags.NoHtml,
+            ListItem = BuildWrappingMarkdownListItem,
             Image = (alt, _) => Text(
                     string.IsNullOrWhiteSpace(alt) ? "[Image]" : $"[Image: {alt}]",
                     14,
@@ -565,9 +566,19 @@ internal static Element BuildSafeMarkdown(string? text)
                 .IsTextSelectionEnabled(true),
         };
 
-        // Fully qualified: the markdown factory ships in Microsoft.UI.Reactor.Advanced, and importing
-        // that namespace would make the simple name `Factories` ambiguous with Microsoft.UI.Reactor.Factories.
-        return Microsoft.UI.Reactor.Advanced.Factories.Markdown(ChatMarkdownSanitizer.Sanitize(text), options);
+        return Microsoft.UI.Reactor.Factories.Markdown(ChatMarkdownSanitizer.Sanitize(text), options);
+    }
+
+    private static Element BuildWrappingMarkdownListItem(Element defaultElement)
+    {
+        // preview.12 measures list content at infinite width in an HStack. Use the
+        // Auto/Star layout from microsoft/microsoft-ui-reactor#1197 until #1424 retires the pin.
+        if (defaultElement is not StackElement { Orientation: Orientation.Horizontal, Children.Length: 2 } row)
+            throw new InvalidOperationException("Unexpected Reactor Markdown list item shape. Review the preview.12 workaround.");
+
+        return Grid([GridSize.Auto, GridSize.Star()], [],
+            row.Children[0],
+            row.Children[1].Grid(column: 1)) with { ColumnSpacing = row.Spacing };
     }
 
     private static Element BuildAssistantFooter(
@@ -652,7 +663,7 @@ private static Element CompactIconAction(
             .OnLostFocus((_, _) => onLostFocus())
             .Opacity(isVisible ? 1 : 0)
             .IsTabStop(true)
-            .IsHitTestVisible(isVisible);
+            .Set(button => button.IsHitTestVisible = isVisible);
     }
 
     private static (string Message, IReadOnlyList<ChatAttachmentPresentation> Attachments) ParseAttachments(string? text)
@@ -1024,7 +1035,7 @@ private static Element HoverMetadata(Element child, bool isHovered)
     {
         return Border(child)
             .Opacity(isHovered ? 1 : 0)
-            .IsHitTestVisible(false);
+            .Set(border => border.IsHitTestVisible = false);
     }
 
     private static TextBlockElement Text(

src/OpenClaw.Tray.WinUI/OpenClaw.Tray.WinUI.csproj

@@ -94,8 +94,10 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="10.0.0" />
-    <PackageReference Include="Microsoft.UI.Reactor" Version="0.1.0-preview.15" />
-    <PackageReference Include="Microsoft.UI.Reactor.Advanced" Version="0.1.0-preview.15" />
+    <!-- Keep both on preview.12 until the WinUI ItemsView fix ships and is validated.
+         Retirement gates and Markdown ListItem workaround: openclaw/openclaw-windows-node#1424. -->
+    <PackageReference Include="Microsoft.UI.Reactor" Version="0.1.0-preview.12" />
+    <PackageReference Include="Microsoft.UI.Reactor.Advanced" Version="0.1.0-preview.12" />
     <PackageReference Include="Microsoft.WindowsAppSDK" Version="$(MicrosoftWindowsAppSDKVersion)" />
     <PackageReference Include="Microsoft.Windows.SDK.BuildTools" Version="$(MicrosoftWindowsSdkBuildToolsVersion)" />
     <PackageReference Include="OpenTelemetry" Version="1.16.0" />

tests/OpenClaw.Tray.Tests/ReactorChatMarkdownContractTests.cs

@@ -23,6 +23,7 @@ public void AssistantMessages_UseSanitizedGitHubFlavoredMarkdown()
         Assert.Contains("Image = (alt, _) => Text(", timeline, StringComparison.Ordinal);
         Assert.Contains("LinkBuilder = (children, _) => HStack(children)", timeline, StringComparison.Ordinal);
         Assert.Contains("HtmlBlock = raw => Text(", timeline, StringComparison.Ordinal);
+        Assert.Contains("ListItem = BuildWrappingMarkdownListItem", timeline, StringComparison.Ordinal);
         Assert.Contains(
             ".AutomationName(BuildAccessibleAssistantText(entry.Text, metadata?.AssistantContent))",
             timeline,

tests/OpenClaw.Tray.UITests/ReactorMarkdownListProofTests.cs

@@ -0,0 +1,147 @@
+using Microsoft.UI.Reactor.Hosting;
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Controls;
+using Microsoft.UI.Xaml.Documents;
+using OpenClawTray.Chat;
+using OpenClawTray.Helpers;
+using static OpenClaw.Tray.UITests.TestSupport;
+
+namespace OpenClaw.Tray.UITests;
+
+[Collection(UICollection.Name)]
+public sealed class ReactorMarkdownListProofTests
+{
+    private const string LongText =
+        "This list item contains enough words to wrap across several lines in a narrow chat bubble " +
+        "while preserving the final words of the message.";
+
+    private readonly UIThreadFixture _ui;
+
+    public ReactorMarkdownListProofTests(UIThreadFixture ui) => _ui = ui;
+
+    [Theory]
+    [InlineData("- ", "\u2022 ")]
+    [InlineData("7. ", "7. ")]
+    public async Task ListContent_WrapsWithinRemainingWidthAndReflowsOnResize(string prefix, string marker)
+    {
+        await _ui.ResetContainerAsync();
+        ReactorHostControl? host = null;
+        UIElement? root = null;
+        double narrowHeight = 0;
+        try
+        {
+            await _ui.RunOnUIAsync(() =>
+            {
+                TestApp.EnsureFluentBrushFallbacks(Application.Current.Resources);
+                host = new ReactorHostControl { Width = 240, VerticalAlignment = VerticalAlignment.Top };
+                root = host.Reconciler.Mount(
+                    ReactorChatTimeline.BuildSafeMarkdown(prefix + LongText), static () => { });
+                host.Content = root;
+                _ui.Container.Children.Add(host);
+            });
+            await _ui.YieldToRenderAsync();
+            await _ui.RunOnUIAsync(() =>
+            {
+                _ui.Container.UpdateLayout();
+                var row = Assert.Single(FindLogical<Grid>(root!), IsListRow);
+                var markerBlock = Assert.IsType<TextBlock>(row.Children[0]);
+                var content = Assert.IsType<RichTextBlock>(row.Children[1]);
+                Assert.Equal(marker, markerBlock.Text);
+                Assert.Equal(LongText, CollectText(content));
+                Assert.Equal(TextWrapping.Wrap, content.TextWrapping);
+                Assert.True(content.IsTextSelectionEnabled);
+                Assert.Equal(1, Grid.GetColumn(content));
+                Assert.InRange(content.ActualWidth, 1, 239);
+                Assert.True(content.ActualWidth + markerBlock.ActualWidth + row.ColumnSpacing <= 241);
+                narrowHeight = content.ActualHeight;
+                Assert.True(narrowHeight > content.FontSize * 2);
+            });
+            await _ui.RunOnUIAsync(() => VisualTestCapture.CaptureAsync(_ui.Container, "ReactorMarkdownListNarrow"));
+            await _ui.RunOnUIAsync(() => { host!.Width = 600; });
+            await _ui.YieldToRenderAsync();
+            await _ui.RunOnUIAsync(() =>
+            {
+                _ui.Container.UpdateLayout();
+                var row = Assert.Single(FindLogical<Grid>(root!), IsListRow);
+                var content = Assert.IsType<RichTextBlock>(row.Children[1]);
+                Assert.True(content.ActualHeight < narrowHeight);
+                Assert.Equal(LongText, CollectText(content));
+                Assert.InRange(content.ActualWidth, 241, 600);
+            });
+            await _ui.RunOnUIAsync(() => VisualTestCapture.CaptureAsync(_ui.Container, "ReactorMarkdownListWide"));
+        }
+        finally
+        {
+            if (host is not null)
+                await _ui.RunOnUIAsync(() =>
+                {
+                    _ui.Container.Children.Remove(host);
+                    host.Content = null;
+                    host.Dispose();
+                });
+        }
+    }
+
+    [Fact]
+    public async Task NestedAndLooseLists_PreserveMarkersFormattingAndBlockContent()
+    {
+        await _ui.ResetContainerAsync();
+        ReactorHostControl? host = null;
+        try
+        {
+            await _ui.RunOnUIAsync(() =>
+            {
+                TestApp.EnsureFluentBrushFallbacks(Application.Current.Resources);
+                host = new ReactorHostControl { Width = 280, VerticalAlignment = VerticalAlignment.Top };
+                var root = host.Reconciler.Mount(ReactorChatTimeline.BuildSafeMarkdown(
+                    "- **outer bold**\n\n  second paragraph\n\n  - nested item\n\n" +
+                    "- final item\n\n  > quoted content"), static () => { });
+                host.Content = root;
+                _ui.Container.Children.Add(host);
+            });
+            await _ui.YieldToRenderAsync();
+            await _ui.RunOnUIAsync(() =>
+            {
+                _ui.Container.UpdateLayout();
+                var rows = FindLogical<Grid>(host!).Where(IsListRow).ToArray();
+                Assert.Equal(3, rows.Length);
+                Assert.All(rows, row =>
+                {
+                    Assert.Equal("\u2022 ", Assert.IsType<TextBlock>(row.Children[0]).Text);
+                    Assert.Equal(1, Grid.GetColumn((FrameworkElement)row.Children[1]));
+                    Assert.InRange(((FrameworkElement)row.Children[1]).ActualWidth, 1, 279);
+                });
+                var texts = FindLogical<RichTextBlock>(host!).ToArray();
+                Assert.Contains(texts, text => CollectText(text) == "second paragraph");
+                Assert.Contains(texts, text => CollectText(text) == "nested item");
+                Assert.Contains(texts, text => CollectText(text) == "quoted content");
+                var bold = Assert.Single(texts, text => CollectText(text) == "outer bold");
+                Assert.Contains(GetRuns(bold), run => run.FontWeight.Weight > 400);
+            });
+            await _ui.RunOnUIAsync(() => VisualTestCapture.CaptureAsync(_ui.Container, "ReactorMarkdownListNested"));
+        }
+        finally
+        {
+            if (host is not null)
+                await _ui.RunOnUIAsync(() =>
+                {
+                    _ui.Container.Children.Remove(host);
+                    host.Content = null;
+                    host.Dispose();
+                });
+        }
+    }
+
+    private static bool IsListRow(Grid grid) =>
+        grid.ColumnDefinitions.Count == 2 &&
+        grid.ColumnDefinitions[0].Width.IsAuto &&
+        grid.ColumnDefinitions[1].Width.IsStar &&
+        grid.Children.Count == 2 &&
+        grid.Children[0] is TextBlock;
+
+    private static IEnumerable<Run> GetRuns(RichTextBlock text) =>
+        text.Blocks.OfType<Paragraph>().SelectMany(paragraph => paragraph.Inlines.OfType<Run>());
+
+    private static string CollectText(RichTextBlock text) =>
+        string.Concat(GetRuns(text).Select(run => run.Text));
+}