fix.patch

diff --git a/OpenRA.Mods.CA/Widgets/Logic/Ingame/ProductionTabsLogicCA.cs b/OpenRA.Mods.CA/Widgets/Logic/Ingame/ProductionTabsLogicCA.cs
index 2ed4c5f2..00000000 100644
--- a/OpenRA.Mods.CA/Widgets/Logic/Ingame/ProductionTabsLogicCA.cs
+++ b/OpenRA.Mods.CA/Widgets/Logic/Ingame/ProductionTabsLogicCA.cs
@@ -10,6 +10,7 @@
 
 using System;
 using System.Linq;
+using OpenRA;
 using OpenRA.Mods.Common.Widgets;
 using OpenRA.Widgets;
 
@@ -17,6 +18,9 @@ namespace OpenRA.Mods.CA.Widgets.Logic
 {
 	public class ProductionTabsLogicCA : ChromeLogic
 	{
+		const string PromotionGroupName = "Promotion";
+		const string CommanderTreeOverlayId = "COMMANDER_TREE_OVERLAY";
+
 		readonly ProductionTabsCAWidget tabs;
 		readonly World world;
 
@@ -25,6 +29,29 @@ namespace OpenRA.Mods.CA.Widgets.Logic
 		{
 			if (button == null)
 				return;
+
+			if (string.Equals(button.ProductionGroup, PromotionGroupName, StringComparison.OrdinalIgnoreCase))
+			{
+				button.IsDisabled = () => false;
+
+				button.OnMouseDown = mi =>
+				{
+					if (mi.Button == MouseButton.Left)
+						OpenCommanderTree();
+				};
+				button.OnMouseUp = _ => { };
+				button.OnClick = () => { };
+				button.OnKeyPress = e =>
+				{
+					if (e.Event != KeyInputEvent.Down)
+						return;
+
+					OpenCommanderTree();
+				};
+				button.IsHighlighted = () => Ui.CurrentWindow() != null && Ui.CurrentWindow().Id == CommanderTreeOverlayId;
+
+				var chromeName = button.ProductionGroup.ToLowerInvariant();
+				var icon = button.Get<ImageWidget>("ICON");
+				icon.GetImageName = () => tabs.Groups[button.ProductionGroup].Alert ? chromeName + "-alert" : chromeName;
+
+				return;
+			}
 
 			Action<bool> selectTab = reverse =>
 			{
@@ -40,7 +67,7 @@ namespace OpenRA.Mods.CA.Widgets.Logic
 			button.IsHighlighted = () => tabs.QueueGroup == button.ProductionGroup;
 
 			var chromeName = button.ProductionGroup.ToLowerInvariant();
-			var icon = button.Get<ImageWidget>("ICON");
-			icon.GetImageName = () => button.IsDisabled() ? chromeName + "-disabled" :
-				tabs.Groups[button.ProductionGroup].Alert ? chromeName + "-alert" : chromeName;
+			var icon = button.Get<ImageWidget>("ICON");
+			icon.GetImageName = () => button.IsDisabled() ? chromeName + "-disabled" :
+				tabs.Groups[button.ProductionGroup].Alert ? chromeName + "-alert" : chromeName;
 		}
 
+		void OpenCommanderTree()
+		{
+			var current = Ui.CurrentWindow();
+			if (current != null && current.Id == CommanderTreeOverlayId)
+			{
+				Ui.CloseWindow();
+				return;
+			}
+
+			Ui.OpenWindow(CommanderTreeOverlayId);
+			Ui.ResetTooltips();
+		}
+
 		[ObjectCreator.UseCtor]
 		public ProductionTabsLogicCA(Widget widget, World world)
 		{