Add property requirements to safe traits

OpenRA.Mods.Common/Traits/Armament.cs

@@ -28,8 +28,8 @@ namespace OpenRA.Mods.Common.Traits
 	{
 		public readonly string Name = "primary";
 
-		[WeaponReference]
+		[WeaponReference, FieldLoader.Require]
-		[Desc("Has to be defined here and in weapons.yaml.")]
+		[Desc("Has to be defined in weapons.yaml as well.")]
 		public readonly string Weapon = null;
 
 		[Desc("Which limited ammo pool (if present) should this armament be assigned to.")]

OpenRA.Mods.Common/Traits/Attack/AttackGarrisoned.cs

@@ -27,14 +27,17 @@ namespace OpenRA.Mods.Common.Traits
 	[Desc("Cargo can fire their weapons out of fire ports.")]
 	public class AttackGarrisonedInfo : AttackFollowInfo, Requires<CargoInfo>
 	{
+		[FieldLoader.Require]
 		[Desc("Fire port offsets in local coordinates.")]
-		public readonly WVec[] PortOffsets = { };
+		public readonly WVec[] PortOffsets = null;
 
+		[FieldLoader.Require]
 		[Desc("Fire port yaw angles.")]
-		public readonly WAngle[] PortYaws = { };
+		public readonly WAngle[] PortYaws = null;
 
+		[FieldLoader.Require]
 		[Desc("Fire port yaw cone angle.")]
-		public readonly WAngle[] PortCones = { };
+		public readonly WAngle[] PortCones = null;
 
 		public readonly string MuzzlePalette = "effect";
 

OpenRA.Mods.Common/Traits/Buildings/FreeActor.cs

@@ -17,7 +17,7 @@ namespace OpenRA.Mods.Common.Traits
 		"If you want more than one unit to appear copy this section and assign IDs like FreeActor@2, ...")]
 	public class FreeActorInfo : ITraitInfo
 	{
-		[ActorReference]
+		[ActorReference, FieldLoader.Require]
 		[Desc("Name of the actor.")]
 		public readonly string Actor = null;
 

OpenRA.Mods.Common/Traits/Buildings/TargetableBuilding.cs

@@ -16,6 +16,7 @@ namespace OpenRA.Mods.Common.Traits
 {
 	public class TargetableBuildingInfo : ITraitInfo, ITargetableInfo, Requires<BuildingInfo>
 	{
+		[FieldLoader.Require]
 		public readonly string[] TargetTypes = { };
 		public string[] GetTargetTypes() { return TargetTypes; }
 

OpenRA.Mods.Common/Traits/Crates/ExplodeCrateAction.cs

@@ -17,7 +17,7 @@ namespace OpenRA.Mods.Common.Traits
 	class ExplodeCrateActionInfo : CrateActionInfo
 	{
 		[Desc("The weapon to fire upon collection.")]
-		[WeaponReference] public string Weapon = null;
+		[WeaponReference, FieldLoader.Require] public string Weapon = null;
 
 		public override object Create(ActorInitializer init) { return new ExplodeCrateAction(init.Self, this); }
 	}

OpenRA.Mods.Common/Traits/Crates/GiveUnitCrateAction.cs

@@ -19,7 +19,7 @@ namespace OpenRA.Mods.Common.Traits
 	class GiveUnitCrateActionInfo : CrateActionInfo
 	{
 		[Desc("The list of units to spawn.")]
-		[ActorReference]
+		[ActorReference, FieldLoader.Require]
 		public readonly string[] Units = { };
 
 		[Desc("Races that are allowed to trigger this action")]

OpenRA.Mods.Common/Traits/Crates/GrantUpgradeCrateAction.cs

@@ -16,7 +16,7 @@ namespace OpenRA.Mods.Common.Traits
 	[Desc("Grants an upgrade to the collector.")]
 	public class GrantUpgradeCrateActionInfo : CrateActionInfo
 	{
-		[UpgradeGrantedReference]
+		[UpgradeGrantedReference, FieldLoader.Require]
 		[Desc("The upgrades to apply.")]
 		public readonly string[] Upgrades = { };
 

OpenRA.Mods.Common/Traits/Crates/SupportPowerCrateAction.cs

@@ -17,7 +17,7 @@ namespace OpenRA.Mods.Common.Traits
 	class SupportPowerCrateActionInfo : CrateActionInfo
 	{
 		[Desc("Which proxy actor, which grants the support power, to spawn.")]
-		[ActorReference] public readonly string Proxy = null;
+		[ActorReference, FieldLoader.Require] public readonly string Proxy = null;
 
 		public override object Create(ActorInitializer init) { return new SupportPowerCrateAction(init.Self, this); }
 	}

OpenRA.Mods.Common/Traits/CustomBuildTimeValue.cs

@@ -15,6 +15,7 @@ namespace OpenRA.Mods.Common.Traits
 	[Desc("Overrides the build time calculated by actor value.")]
 	public class CustomBuildTimeValueInfo : TraitInfo<CustomBuildTimeValue>
 	{
+		[FieldLoader.Require]
 		[Desc("Measured in ticks.")]
 		public readonly int Value = 0;
 	}

OpenRA.Mods.Common/Traits/CustomSelectionSize.cs

@@ -18,6 +18,7 @@ namespace OpenRA.Mods.Common.Traits
 	"Examples: bridge huts and crates.")]
 	public class CustomSelectionSizeInfo : ITraitInfo
 	{
+		[FieldLoader.Require]
 		public readonly int[] CustomBounds = null;
 
 		public object Create(ActorInitializer init) { return new CustomSelectionSize(this); }

OpenRA.Mods.Common/Traits/CustomSellValue.cs

@@ -15,6 +15,7 @@ namespace OpenRA.Mods.Common.Traits
 	[Desc("Allow a non-standard sell/repair value to avoid buy-sell exploits.")]
 	public class CustomSellValueInfo : TraitInfo<CustomSellValue>
 	{
+		[FieldLoader.Require]
 		public readonly int Value = 0;
 	}
 

OpenRA.Mods.Common/Traits/GlobalUpgradable.cs

@@ -16,10 +16,11 @@ namespace OpenRA.Mods.Common.Traits
 	[Desc("Grants upgrades to the actor this is attached to when prerequisites are available.")]
 	public class GlobalUpgradableInfo : ITraitInfo, Requires<UpgradeManagerInfo>
 	{
-		[UpgradeGrantedReference]
+		[UpgradeGrantedReference, FieldLoader.Require]
 		[Desc("List of upgrades to apply.")]
 		public readonly string[] Upgrades = { };
 
+		[FieldLoader.Require]
 		[Desc("List of required prerequisites.")]
 		public readonly string[] Prerequisites = { };
 

OpenRA.Mods.Common/Traits/Infantry/TakeCover.cs

@@ -24,8 +24,9 @@ namespace OpenRA.Mods.Common.Traits
 		[Desc("Prone movement speed as a percentage of the normal speed.")]
 		public readonly int SpeedModifier = 50;
 
+		[FieldLoader.Require]
 		[Desc("Damage types that trigger prone state. Defined on the warheads.")]
-		public readonly string[] DamageTriggers = new string[0];
+		public readonly string[] DamageTriggers = null;
 
 		[FieldLoader.LoadUsing("LoadModifiers")]
 		[Desc("Damage modifiers for each damage type (defined on the warheads) while the unit is prone.")]

OpenRA.Mods.Common/Traits/Infantry/TerrainModifiesDamage.cs

@@ -17,7 +17,7 @@ namespace OpenRA.Mods.Common.Traits
 {
 	public class TerrainModifiesDamageInfo : ITraitInfo
 	{
-		[FieldLoader.LoadUsing("LoadPercents")]
+		[FieldLoader.LoadUsing("LoadPercents", true)]
 		[Desc("Damage percentage for specific terrain types. 120 = 120%, 80 = 80%, etc.")]
 		public readonly Dictionary<string, int> TerrainModifier = null;
 
@@ -28,12 +28,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		static object LoadPercents(MiniYaml y)
 		{
-			MiniYaml percents;
+			return y.ToDictionary()["TerrainModifier"].Nodes.ToDictionary(
-
-			if (!y.ToDictionary().TryGetValue("TerrainModifier", out percents))
-				return new Dictionary<string, int>();
-
-			return percents.Nodes.ToDictionary(
 				kv => FieldLoader.GetValue<string>("(key)", kv.Key),
 				kv => FieldLoader.GetValue<int>("(value)", kv.Value.Value));
 		}

OpenRA.Mods.Common/Traits/Mobile.cs

@@ -32,7 +32,7 @@ namespace OpenRA.Mods.Common.Traits
 	[Desc("Unit is able to move.")]
 	public class MobileInfo : IMoveInfo, IOccupySpaceInfo, IFacingInfo, UsesInit<FacingInit>, UsesInit<LocationInit>, UsesInit<SubCellInit>
 	{
-		[FieldLoader.LoadUsing("LoadSpeeds")]
+		[FieldLoader.LoadUsing("LoadSpeeds", true)]
 		[Desc("Set Water: 0 for ground units and lower the value on rough terrain.")]
 		public readonly Dictionary<string, TerrainInfo> TerrainSpeeds;
 

OpenRA.Mods.Common/Traits/Player/ProductionQueue.cs

@@ -20,6 +20,7 @@ namespace OpenRA.Mods.Common.Traits
 		"at the same time. Will only work together with the Production: trait.")]
 	public class ProductionQueueInfo : ITraitInfo
 	{
+		[FieldLoader.Require]
 		[Desc("What kind of production will be added (e.g. Building, Infantry, Vehicle, ...)")]
 		public readonly string Type = null;
 

OpenRA.Mods.Common/Traits/Plug.cs

@@ -16,6 +16,7 @@ namespace OpenRA.Mods.Common.Traits
 {
 	public class PlugInfo : TraitInfo<Plug>
 	{
+		[FieldLoader.Require]
 		[Desc("Plug type (matched against Upgrades in Pluggable)")]
 		public readonly string Type = null;
 	}

OpenRA.Mods.Common/Traits/Pluggable.cs

@@ -19,18 +19,13 @@ namespace OpenRA.Mods.Common.Traits
 		[Desc("Footprint cell offset where a plug can be placed.")]
 		public readonly CVec Offset = CVec.Zero;
 
-		[FieldLoader.LoadUsing("LoadUpgrades")]
+		[FieldLoader.LoadUsing("LoadUpgrades", true)]
 		[Desc("Upgrades to grant for each accepted plug type.")]
 		public readonly Dictionary<string, string[]> Upgrades = null;
 
 		static object LoadUpgrades(MiniYaml y)
 		{
-			MiniYaml upgrades;
+			return y.ToDictionary()["Upgrades"].Nodes.ToDictionary(
-
-			if (!y.ToDictionary().TryGetValue("Upgrades", out upgrades))
-				return new Dictionary<string, string[]>();
-
-			return upgrades.Nodes.ToDictionary(
 				kv => kv.Key,
 				kv => FieldLoader.GetValue<string[]>("(value)", kv.Value.Value));
 		}

OpenRA.Mods.Common/Traits/Production.cs

@@ -21,6 +21,7 @@ namespace OpenRA.Mods.Common.Traits
 	[Desc("This unit has access to build queues.")]
 	public class ProductionInfo : ITraitInfo
 	{
+		[FieldLoader.Require]
 		[Desc("e.g. Infantry, Vehicles, Aircraft, Buildings")]
 		public readonly string[] Produces = { };
 

OpenRA.Mods.Common/Traits/ProximityCaptor.cs

@@ -16,6 +16,7 @@ namespace OpenRA.Mods.Common.Traits
 	[Desc("Actor can capture ProximityCapturable actors.")]
 	public class ProximityCaptorInfo : ITraitInfo
 	{
+		[FieldLoader.Require]
 		public readonly string[] Types = { };
 		public object Create(ActorInitializer init) { return new ProximityCaptor(this); }
 	}

OpenRA.Mods.Common/Traits/Render/TimedUpgradeBar.cs

@@ -18,6 +18,7 @@ namespace OpenRA.Mods.Common.Traits
 	[Desc("Visualizes the remaining time for an upgrade.")]
 	class TimedUpgradeBarInfo : ITraitInfo, Requires<UpgradeManagerInfo>
 	{
+		[FieldLoader.Require]
 		[Desc("Upgrade that this bar corresponds to")]
 		public readonly string Upgrade = null;
 

OpenRA.Mods.Common/Traits/Sound/AmbientSound.cs

@@ -15,6 +15,7 @@ namespace OpenRA.Mods.Common.Traits
 	[Desc("Plays a looping audio file at the actor position. Attach this to the `World` actor to cover the whole map.")]
 	class AmbientSoundInfo : ITraitInfo
 	{
+		[FieldLoader.Require]
 		public readonly string SoundFile = null;
 
 		public object Create(ActorInitializer init) { return new AmbientSound(init.Self, this); }

OpenRA.Mods.Common/Traits/StoresResources.cs

@@ -18,9 +18,11 @@ namespace OpenRA.Mods.Common.Traits
 	[Desc("Used for silos.")]
 	class StoresResourcesInfo : ITraitInfo
 	{
+		[FieldLoader.Require]
 		[Desc("Number of little squares used to display how filled unit is.")]
 		public readonly int PipCount = 0;
 		public readonly PipType PipColor = PipType.Yellow;
+		[FieldLoader.Require]
 		public readonly int Capacity = 0;
 		public object Create(ActorInitializer init) { return new StoresResources(init.Self, this); }
 	}

OpenRA.Mods.Common/Traits/SupportPowers/GrantUpgradePower.cs

@@ -19,7 +19,7 @@ namespace OpenRA.Mods.Common.Traits
 {
 	class GrantUpgradePowerInfo : SupportPowerInfo
 	{
-		[UpgradeGrantedReference]
+		[UpgradeGrantedReference, FieldLoader.Require]
 		[Desc("The upgrades to apply.")]
 		public readonly string[] Upgrades = { };
 

OpenRA.Mods.Common/Traits/SupportPowers/SpawnActorPower.cs

@@ -12,12 +12,14 @@ using OpenRA.Effects;
 using OpenRA.Mods.Common.Activities;
 using OpenRA.Mods.Common.Effects;
 using OpenRA.Primitives;
+using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.Traits
 {
 	[Desc("Spawns an actor that stays for a limited amount of time.")]
 	public class SpawnActorPowerInfo : SupportPowerInfo
 	{
+		[ActorReference, FieldLoader.Require]
 		[Desc("Actor to spawn.")]
 		public readonly string Actor = null;
 

OpenRA.Mods.Common/Traits/ThrowsParticle.cs

@@ -15,6 +15,7 @@ namespace OpenRA.Mods.Common.Traits
 {
 	class ThrowsParticleInfo : ITraitInfo, Requires<WithSpriteBodyInfo>, Requires<IBodyOrientationInfo>
 	{
+		[FieldLoader.Require]
 		public readonly string Anim = null;
 
 		[Desc("Initial position relative to body")]

OpenRA.Mods.Common/Traits/ThrowsShrapnel.cs

@@ -17,7 +17,7 @@ namespace OpenRA.Mods.Common.Traits
 	[Desc("Throws particles when the actor is destroyed that do damage on impact.")]
 	public class ThrowsShrapnelInfo : ITraitInfo
 	{
-		[WeaponReference]
+		[WeaponReference, FieldLoader.Require]
 		public string[] Weapons = { };
 		public int[] Pieces = { 3, 10 };
 		public WDist[] Range = { WDist.FromCells(2), WDist.FromCells(5) };

OpenRA.Mods.Common/Traits/TransformOnPassenger.cs

@@ -16,7 +16,7 @@ namespace OpenRA.Mods.Common.Traits
 {
 	public class TransformOnPassengerInfo : ITraitInfo
 	{
-		[ActorReference] public readonly string[] PassengerTypes = { };
+		[ActorReference, FieldLoader.Require] public readonly string[] PassengerTypes = { };
 		[ActorReference] public readonly string OnEnter = null;
 		[ActorReference] public readonly string OnExit = null;
 		public readonly bool SkipMakeAnims = false;

OpenRA.Mods.Common/Traits/Transforms.cs

@@ -18,7 +18,7 @@ namespace OpenRA.Mods.Common.Traits
 	[Desc("Actor becomes a specified actor type when this trait is triggered.")]
 	public class TransformsInfo : ITraitInfo
 	{
-		[Desc("Actor to transform into."), ActorReference]
+		[Desc("Actor to transform into."), ActorReference, FieldLoader.Require]
 		public readonly string IntoActor = null;
 
 		[Desc("Offset to spawn the transformed actor relative to the current cell.")]

OpenRA.Mods.Common/Traits/Upgrades/DeployToUpgrade.cs

@@ -18,7 +18,7 @@ namespace OpenRA.Mods.Common.Traits
 {
 	public class DeployToUpgradeInfo : ITraitInfo, Requires<UpgradeManagerInfo>
 	{
-		[UpgradeGrantedReference]
+		[UpgradeGrantedReference, FieldLoader.Require]
 		[Desc("The upgrades to grant when deploying and revoke when undeploying.")]
 		public readonly string[] Upgrades = { };
 

OpenRA.Mods.Common/Traits/Upgrades/UpgradeActorsNear.cs

@@ -18,7 +18,7 @@ namespace OpenRA.Mods.Common.Traits
 	[Desc("Applies an upgrade to actors within a specified range.")]
 	public class UpgradeActorsNearInfo : ITraitInfo
 	{
-		[UpgradeGrantedReference]
+		[UpgradeGrantedReference, FieldLoader.Require]
 		[Desc("The upgrades to grant.")]
 		public readonly string[] Upgrades = { };
 

OpenRA.Mods.Common/Traits/Valued.cs

@@ -15,6 +15,7 @@ namespace OpenRA.Mods.Common.Traits
 	[Desc("How much the unit is worth.")]
 	public class ValuedInfo : TraitInfo<Valued>
 	{
+		[FieldLoader.Require]
 		[Desc("Used in production, but also for bounties so remember to set it > 0 even for NPCs.")]
 		public readonly int Cost = 0;
 	}

OpenRA.Mods.Common/Traits/VeteranProductionIconOverlay.cs

@@ -19,6 +19,7 @@ namespace OpenRA.Mods.Common.Traits
 		"The icon change occurs when LevelupWhenCreated.Prerequisites are met.")]
 	public class VeteranProductionIconOverlayInfo : ITraitInfo, Requires<TechTreeInfo>
 	{
+		[FieldLoader.Require]
 		[Desc("Image used for the overlay.")]
 		public readonly string Image = null;
 

OpenRA.Mods.Common/Traits/Voiced.cs

@@ -18,6 +18,7 @@ namespace OpenRA.Mods.Common.Traits
 	[Desc("This actor has a voice.")]
 	public class VoicedInfo : ITraitInfo
 	{
+		[FieldLoader.Require]
 		[Desc("Which voice set to use.")]
 		[VoiceSetReference] public readonly string VoiceSet = null;
 

OpenRA.Mods.Common/Traits/World/PaletteFromCurrentTileset.cs

@@ -18,6 +18,7 @@ namespace OpenRA.Mods.Common.Traits
 	[Desc("Loads the palette specified in the tileset definition")]
 	class PaletteFromCurrentTilesetInfo : ITraitInfo
 	{
+		[FieldLoader.Require]
 		[Desc("internal palette name")]
 		public readonly string Name = null;
 		[Desc("Map listed indices to shadow. Ignores previous color.")]

OpenRA.Mods.Common/Traits/World/PaletteFromFile.cs

@@ -17,10 +17,12 @@ namespace OpenRA.Mods.Common.Traits
 {
 	class PaletteFromFileInfo : ITraitInfo
 	{
+		[FieldLoader.Require]
 		[Desc("internal palette name")]
 		public readonly string Name = null;
 		[Desc("If defined, load the palette only for this tileset.")]
 		public readonly string Tileset = null;
+		[FieldLoader.Require]
 		[Desc("filename to load")]
 		public readonly string Filename = null;
 		[Desc("Map listed indices to shadow. Ignores previous color.")]

OpenRA.Mods.Common/Traits/World/PaletteFromPaletteWithAlpha.cs

@@ -19,9 +19,11 @@ namespace OpenRA.Mods.D2k.Traits
 	[Desc("Create a palette by applying alpha transparency to another palette.")]
 	class PaletteFromPaletteWithAlphaInfo : 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;
 

OpenRA.Mods.Common/Traits/World/PaletteFromPlayerPaletteWithAlpha.cs

@@ -19,9 +19,11 @@ namespace OpenRA.Mods.D2k.Traits
 	[Desc("Create player palettes by applying alpha transparency to another player palette.")]
 	class PaletteFromPlayerPaletteWithAlphaInfo : ITraitInfo
 	{
+		[FieldLoader.Require]
 		[Desc("The prefix for the resulting player palettes")]
 		public readonly string BaseName = null;
 
+		[FieldLoader.Require]
 		[Desc("The name of the player palette to base off.")]
 		public readonly string BasePalette = null;
 

OpenRA.Mods.Common/Traits/World/PaletteFromRGBA.cs

@@ -18,6 +18,7 @@ namespace OpenRA.Mods.Common.Traits
 	[Desc("Creates a single color palette without any base palette file.")]
 	class PaletteFromRGBAInfo : ITraitInfo
 	{
+		[FieldLoader.Require]
 		[Desc("internal palette name")]
 		public readonly string Name = null;
 		[Desc("If defined, load the palette only for this tileset.")]

OpenRA.Mods.Common/Traits/World/PlayerPaletteFromCurrentTileset.cs

@@ -16,6 +16,7 @@ namespace OpenRA.Mods.Common.Traits
 {
 	class PlayerPaletteFromCurrentTilesetInfo : ITraitInfo
 	{
+		[FieldLoader.Require]
 		[Desc("internal palette name")]
 		public readonly string Name = null;
 		[Desc("Map listed indices to shadow.")]

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;
 

OpenRA.Mods.RA/Traits/Buildings/ClonesProducedUnits.cs

@@ -17,6 +17,7 @@ namespace OpenRA.Mods.RA.Traits
 	[Desc("Creates a free duplicate of produced units.")]
 	public class ClonesProducedUnitsInfo : ITraitInfo, Requires<ProductionInfo>, Requires<ExitInfo>
 	{
+		[FieldLoader.Require]
 		[Desc("Uses the \"Cloneable\" trait to determine whether or not we should clone a produced unit.")]
 		public readonly string[] CloneableTypes = { };
 

OpenRA.Mods.RA/Traits/Cloneable.cs

@@ -16,6 +16,7 @@ namespace OpenRA.Mods.RA.Traits
 	[Desc("Actors with the \"ClonesProducedUnits\" trait will produce a free duplicate of me.")]
 	public class CloneableInfo : TraitInfo<Cloneable>
 	{
+		[FieldLoader.Require]
 		[Desc("This unit's cloneable type is:")]
 		public readonly string[] Types = { };
 	}

OpenRA.Mods.RA/Traits/Infiltration/InfiltrateForSupportPower.cs

@@ -15,7 +15,7 @@ namespace OpenRA.Mods.RA.Traits
 {
 	class InfiltrateForSupportPowerInfo : ITraitInfo
 	{
-		[ActorReference] public readonly string Proxy = null;
+		[ActorReference, FieldLoader.Require] public readonly string Proxy = null;
 
 		public object Create(ActorInitializer init) { return new InfiltrateForSupportPower(this); }
 	}

OpenRA.Mods.RA/Traits/LeavesHusk.cs

@@ -18,7 +18,7 @@ namespace OpenRA.Mods.RA.Traits
 	[Desc("Spawn another actor immediately upon death.")]
 	public class LeavesHuskInfo : ITraitInfo
 	{
-		[ActorReference]
+		[ActorReference, FieldLoader.Require]
 		public readonly string HuskActor = null;
 
 		public object Create(ActorInitializer init) { return new LeavesHusk(init, this); }