Potential crash when binding to or replacing RoslynCodeEditor.Document

[lennartb-]

When binding to the Document property, or manually setting the Document property and then adding text and scrolling a bit, I can consistently reproduce a crash in AvalonEdit. I think this is caused by

roslynpad/src/RoslynPad.Editor.Shared/TextMarkerService.cs

Line 76 in ea04c0b

var markersAtOffset = GetMarkersAtOffset(offset);

Stacktrace:

ICSharpCode.AvalonEdit.dll!ICSharpCode.AvalonEdit.Document.TextDocument.GetLineByNumber(int number) Line 894
ICSharpCode.AvalonEdit.dll!ICSharpCode.AvalonEdit.Document.TextDocument.GetOffset(int line, int column) Line 939
RoslynPad.Editor.Windows.dll!RoslynPad.Editor.TextMarkerService.EditorOnToolTipRequest(object sender, RoslynPad.Editor.ToolTipRequestEventArgs args) Line 86	C#

(the package does not seem up to date with the sources here)
Repro:

<Window
    x:Class="WpfApp1.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:editor="clr-namespace:RoslynPad.Editor;assembly=RoslynPad.Editor.Windows"
    Title="MainWindow"
    Width="800"
    Height="450">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="*" />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>
        <editor:RoslynCodeEditor
            Name="Editor"
            Grid.Row="0"
            Document="{Binding Document}"
            FontSize="24"
            WordWrap="True" />
    </Grid>
</Window>

public partial class MainWindow : Window
{
    public TextDocument Document { get; } = new TextDocument();
    public MainWindow()
    {
        InitializeComponent();
        DataContext = this;
        Document = new TextDocument();
        Document = new TextDocument();
        Document = new TextDocument();
        Document = new TextDocument();
        Document = new TextDocument();
    }
}

Then start the app, write some text (including ~10 newlines) and use the scroll wheel on the mouse to scroll a couple of seconds up and down.

I think it's due to TextMarkerService caching the initial Document, and not updating its local copy when the Document of the Editor is replaced. This causes GetMarkersAtOffset called with an offset that isn't present in its cached version.

Version
OS: Win 11
NuGet RoslynPad.Editor.Windows 1.2.0