Add property requirements to safe traits

OpenRA.Mods.D2k/Traits/Buildings/FreeActorWithDelivery.cs

@@ -22,7 +22,7 @@ namespace OpenRA.Mods.D2k.Traits
 		"If you want more than one unit to be delivered, copy this section and assign IDs like FreeActorWithDelivery@2, ...")]
 	public class FreeActorWithDeliveryInfo : FreeActorInfo
 	{
-		[ActorReference]
+		[ActorReference, FieldLoader.Require]
 		[Desc("Name of the delivering actor. This actor must have the `Carryall` trait")]
 		public readonly string DeliveringActor = null;
 
@@ -43,11 +43,6 @@ namespace OpenRA.Mods.D2k.Traits
 
 		public FreeActorWithDelivery(ActorInitializer init, FreeActorWithDeliveryInfo info)
 		{
-			if (string.IsNullOrEmpty(info.Actor))
-				throw new InvalidDataException("Actor type was not specified!");
-			if (string.IsNullOrEmpty(info.DeliveringActor))
-				throw new InvalidDataException("Delivering actor type was not specified!");
-
 			self = init.Self;
 			Info = info;
 

OpenRA.Mods.D2k/Traits/Buildings/LaysTerrain.cs

@@ -20,6 +20,7 @@ namespace OpenRA.Mods.D2k.Traits
 			"the actor footprint will be filled with this tile.")]
 		public readonly ushort Template = 0;
 
+		[FieldLoader.Require]
 		[Desc("The terrain types that this template will be placed on")]
 		public readonly string[] TerrainTypes = { };
 

OpenRA.Mods.D2k/Traits/Render/WithAttackOverlay.cs

@@ -17,6 +17,7 @@ namespace OpenRA.Mods.D2k.Traits
 	[Desc("Rendered together with an attack.")]
 	public class WithAttackOverlayInfo : ITraitInfo, Requires<RenderSpritesInfo>
 	{
+		[FieldLoader.Require]
 		[Desc("Sequence name to use")]
 		[SequenceReference] public readonly string Sequence = null;
 

OpenRA.Mods.D2k/Traits/World/FogPaletteFromR8.cs

@@ -19,8 +19,10 @@ namespace OpenRA.Mods.D2k.Traits
 {
 	class FogPaletteFromR8Info : ITraitInfo
 	{
+		[FieldLoader.Require]
 		[Desc("Internal palette name")]
 		public readonly string Name = null;
+		[FieldLoader.Require]
 		[Desc("Filename to load")]
 		public readonly string Filename = null;
 		[Desc("Palette byte offset")]

OpenRA.Mods.D2k/Traits/World/PaletteFromR8.cs

@@ -19,8 +19,10 @@ namespace OpenRA.Mods.D2k.Traits
 {
 	class PaletteFromR8Info : ITraitInfo
 	{
+		[FieldLoader.Require]
 		[Desc("Internal palette name")]
 		public readonly string Name = null;
+		[FieldLoader.Require]
 		[Desc("Filename to load")]
 		public readonly string Filename = null;
 		[Desc("Palette byte offset")]

OpenRA.Mods.D2k/Traits/World/PaletteFromScaledPalette.cs

@@ -19,9 +19,11 @@ namespace OpenRA.Mods.D2k.Traits
 	[Desc("Create a palette by applying a scale and offset to the colors in another palette.")]
 	class PaletteFromScaledPaletteInfo : ITraitInfo
 	{
+		[FieldLoader.Require]
 		[Desc("Internal palette name")]
 		public readonly string Name = null;
 
+		[FieldLoader.Require]
 		[Desc("The name of the palette to base off.")]
 		public readonly string BasePalette = null;