Drop redundant Copy in metadata grid context menu

Avalonia DataGrid surfaces a per-cell Copy in its default cell context
menu, so seeding our own at the top of the built menu produced a
duplicate "Copy" entry. Revert the seed; cancel our menu when no MEF
entries are visible (the built-in cell menu still shows).

Assisted-by: Claude:claude-opus-4-7:Claude Code

ILSpy/Views/MetadataTablePage.axaml.cs

@@ -25,7 +25,6 @@ using Avalonia;
 using Avalonia.Collections;
 using Avalonia.Controls;
 using Avalonia.Input;
-using Avalonia.Input.Platform;
 using Avalonia.Markup.Xaml;
 using Avalonia.VisualTree;
 
@@ -123,63 +122,21 @@ namespace ILSpy.Views
 				DataGrid = grid,
 				OriginalSource = hoveredCell,
 			};
-			menu.Items.Clear();
-
-			// Always-available Copy. Avalonia DataGrid's built-in Ctrl+C copies the active
-			// selection as TSV; mirror that here so right-click in a plain column cell still
-			// produces a usable menu (the GoToToken entry shows only on token-kind cells).
-			var copyItem = new MenuItem {
-				Header = "Copy",
-				InputGesture = new KeyGesture(Key.C, KeyModifiers.Control),
-				IsEnabled = grid?.SelectedItem != null,
-			};
-			copyItem.Click += async (_, _) => {
-				if (grid is null)
-					return;
-				var topLevel = TopLevel.GetTopLevel(grid);
-				var clipboard = topLevel?.Clipboard;
-				if (clipboard is null)
-					return;
-				var text = BuildClipboardText(grid);
-				if (!string.IsNullOrEmpty(text))
-					await clipboard.SetTextAsync(text);
-			};
-			menu.Items.Add(copyItem);
-
 			var built = ContextMenuProvider.Build(contextMenuEntries, context);
-			if (built != null)
+			if (built == null)
 			{
-				menu.Items.Add(new Separator());
-				foreach (var item in built.Items.Cast<Control>().ToArray())
-				{
-					built.Items.Remove(item);
-					menu.Items.Add(item);
-				}
+				// No MEF entries are visible for this click. Avalonia DataGrid's default
+				// per-cell context menu still surfaces Copy, so cancel ours rather than
+				// stack a redundant duplicate on top of it.
+				e.Cancel = true;
+				return;
 			}
-		}
-
-		static string BuildClipboardText(DataGrid grid)
-		{
-			// Tab-separated row dump for the selected item — same shape DataGrid's built-in
-			// Ctrl+C produces. Walk every column so the user sees the full row state, not
-			// only the cell under the pointer.
-			if (grid.SelectedItem is not { } row)
-				return string.Empty;
-			var sb = new System.Text.StringBuilder();
-			for (int i = 0; i < grid.Columns.Count; i++)
+			menu.Items.Clear();
+			foreach (var item in built.Items.Cast<Control>().ToArray())
 			{
-				if (i > 0)
-					sb.Append('\t');
-				var col = grid.Columns[i];
-				if (col is DataGridTextColumn text && text.Binding is global::Avalonia.Data.Binding b
-					&& b.Path is { } path
-					&& row.GetType().GetProperty(path) is { } prop)
-				{
-					var v = prop.GetValue(row);
-					sb.Append(v?.ToString());
-				}
+				built.Items.Remove(item);
+				menu.Items.Add(item);
 			}
-			return sb.ToString();
 		}
 
 		void InitializeComponent() => AvaloniaXamlLoader.Load(this);