Draw an ampersand where the text has one

src/DiffEngineViewer.Windows.Tests/AmpersandTests.cs

@@ -0,0 +1,34 @@
+/// <summary>
+/// An ampersand in a solution name, a path or an applier message. WinForms reads one as a mnemonic
+/// wherever it renders text, so "R&amp;D" draws as "R_D" - with D live as an accelerator, which is
+/// worse than the missing character.
+/// </summary>
+[NotInParallel]
+[TUnit.Core.Executors.STAThreadExecutor]
+public class AmpersandTests
+{
+    [Test]
+    public async Task A_menu_label_keeps_its_ampersand()
+    {
+        using var strip = ViewerMenu.Build(new(0, ["Accept all in R&D"]));
+
+        var item = strip.Items
+            .Cast<System.Windows.Forms.ToolStripItem>()
+            .Single();
+        // Doubled, which is how a literal one is written. What is drawn is one
+        await Assert.That(item.Text).IsEqualTo("Accept all in R&&D");
+    }
+
+    [Test]
+    public async Task The_status_line_does_not_read_one_as_a_mnemonic()
+    {
+        using var form = new ViewerForm("title", 800, 600);
+
+        var status = form.Controls
+            .Find("status", true)
+            .OfType<System.Windows.Forms.Label>()
+            .Single();
+
+        await Assert.That(status.UseMnemonic).IsFalse();
+    }
+}

src/DiffEngineViewer.Windows/ViewerForm.cs

@@ -20,10 +20,15 @@ sealed class ViewerForm : Form
 
     readonly Label status = new()
     {
+        Name = "status",
         Dock = DockStyle.Fill,
         TextAlign = ContentAlignment.MiddleRight,
         ForeColor = Palette.Dim,
-        AutoSize = false
+        AutoSize = false,
+        // The status line is built from paths, solution names and whatever the applier said, and a
+        // Label reads an ampersand in any of those as a mnemonic: "R&D" drew as "R_D" with D live
+        // as an accelerator.
+        UseMnemonic = false
     };
 
     readonly List<FormsButton> pool = [];

src/DiffEngineViewer.Windows/ViewerMenu.cs

@@ -41,12 +41,21 @@ public static void Fill(ContextMenuStrip strip, MenuOverlay menu, Action<int> cl
         for (var index = 0; index < menu.Labels.Count; index++)
         {
             var captured = index;
-            var item = new ToolStripMenuItem(menu.Labels[index]);
+            var item = new ToolStripMenuItem(Escape(menu.Labels[index]));
             item.Click += (_, _) => clicked(captured);
             strip.Items.Add(item);
         }
     }
 
+    /// <summary>
+    /// Menu labels carry solution names and file names - "Accept all in R&amp;D" - and a menu item
+    /// reads an ampersand as a mnemonic, so that one drew as "Accept all in R_D" with D live as an
+    /// accelerator. Doubling it is how a literal one is written; ToolStripItem has no
+    /// <c>UseMnemonic</c> to turn the reading off.
+    /// </summary>
+    static string Escape(string label) =>
+        label.Replace("&", "&&");
+
     /// <summary>
     /// A strip on its own, for tests and for anything that wants one without a window.
     /// </summary>