Merge pull request #841 from stavrosfa/fix/unit-buttons

Fix unit action buttons bugs

Author: stavrosfa

C7/UIElements/UnitButtons/UnitButtons.cs

@@ -123,6 +123,7 @@ private void OnUnitMoved(ParameterWrapper<MapUnit> wrappedMapUnit) {
 	}
 
 	private void UpdateButtons(MapUnit unit) {
+		if (!unit.CanBeActive()) return;
 		// Reset the visibility and tooltip whenever the unit changes.
 		foreach (ButtonAndTooltip btt in buttonMap.Values) {
 			btt.button.Visible = false;

C7Engine/C7GameData/Tile.cs

@@ -773,9 +773,7 @@ public TerrainImprovement ImprovementAtLayer(TerrainImprovement.Layer layer) {
 		}
 
 		public TerrainImprovement ImprovementAtLayer(Terraform terraform) {
-			TerrainImprovement.Layer currentLayer = terraform.Improvement.layer;
-			terrainImprovementByLayer.TryGetValue(currentLayer, out TerrainImprovement ti);
-			return ti;
+			return terraform.Improvement == null ? null : ImprovementAtLayer(terraform.Improvement.layer);
 		}
 
 		public bool HasImprovement(TerrainImprovement improvement) {