some accessors

OpenRa.Game/Combat.cs

@@ -78,9 +78,9 @@ namespace OpenRa.Game
 		{
 			var info = self.Info.Traits.WithInterface<AttackBaseInfo>().First();
 			if (info.PrimaryWeapon != null &&
-				WeaponValidForTarget(Rules.WeaponInfo[info.PrimaryWeapon], target)) return true;
+				WeaponValidForTarget(self.GetPrimaryWeapon(), target)) return true;
 			if (info.SecondaryWeapon != null &&
-				WeaponValidForTarget(Rules.WeaponInfo[info.SecondaryWeapon], target)) return true;
+				WeaponValidForTarget(self.GetSecondaryWeapon(), target)) return true;
 
 			return false;
 		}

OpenRa.Game/Exts.cs

@@ -2,6 +2,8 @@
 using System.Windows.Forms;
 using System.Collections.Generic;
 using System.Linq;
+using OpenRa.Game.GameRules;
+using OpenRa.Game.Traits;
 
 namespace OpenRa.Game
 {
@@ -27,5 +29,27 @@ namespace OpenRa.Game
 		{
 			return xs.Aggregate(1f, (a, x) => a * x);
 		}
+
+		public static WeaponInfo GetPrimaryWeapon(this Actor self)
+		{
+			var info = self.Info.Traits.WithInterface<AttackBaseInfo>().FirstOrDefault();
+			if (info == null) return null;
+			
+			var weapon = info.PrimaryWeapon;
+			if (weapon == null) return null;
+
+			return Rules.WeaponInfo[weapon];
+		}
+
+		public static WeaponInfo GetSecondaryWeapon(this Actor self)
+		{
+			var info = self.Info.Traits.WithInterface<AttackBaseInfo>().FirstOrDefault();
+			if (info == null) return null;
+
+			var weapon = info.SecondaryWeapon;
+			if (weapon == null) return null;
+
+			return Rules.WeaponInfo[weapon];
+		}
 	}
 }

OpenRa.Game/Traits/Activities/HeliAttack.cs

@@ -30,7 +30,7 @@ namespace OpenRa.Game.Traits.Activities
 				return this;
 			}
 
-			var range = Rules.WeaponInfo[ self.Info.Traits.WithInterface<AttackBaseInfo>().First().PrimaryWeapon ].Range - 1;
+			var range = self.GetPrimaryWeapon().Range - 1;
 			var dist = target.CenterLocation - self.CenterLocation;
 
 			var desiredFacing = Util.GetFacing(dist, unit.Facing);

OpenRa.Game/Traits/AttackBase.cs

@@ -38,10 +38,8 @@ namespace OpenRa.Game.Traits
 
 		public AttackBase(Actor self)
 		{
-			var info = self.Info.Traits.WithInterface<AttackBaseInfo>().First();
+			var primaryWeapon = self.GetPrimaryWeapon();
-
+			var secondaryWeapon = self.GetSecondaryWeapon();
-			var primaryWeapon = info.PrimaryWeapon != null ? Rules.WeaponInfo[info.PrimaryWeapon] : null;
-			var secondaryWeapon = info.SecondaryWeapon != null ? Rules.WeaponInfo[info.SecondaryWeapon] : null;
 
 			primaryBurst = primaryWeapon != null ? primaryWeapon.Burst : 1;
 			secondaryBurst = secondaryWeapon != null ? secondaryWeapon.Burst : 1;
@@ -181,8 +179,7 @@ namespace OpenRa.Game.Traits
 			if (mi.Button == MouseButton.Left || underCursor == null) return null;
 			if (self == underCursor) return null;
 
-			var info = self.Info.Traits.WithInterface<AttackBaseInfo>().First();
+			var isHeal = self.GetPrimaryWeapon().Damage < 0;
-			var isHeal = Rules.WeaponInfo[info.PrimaryWeapon].Damage < 0;
 			if (((underCursor.Owner == self.Owner) ^ isHeal) 
 				&& !mi.Modifiers.HasModifier( Modifiers.Ctrl )) return null;
 
@@ -207,13 +204,12 @@ namespace OpenRa.Game.Traits
 
 		protected virtual void QueueAttack(Actor self, Order order)
 		{
-			var info = self.Info.Traits.WithInterface<AttackBaseInfo>().First();
 			const int RangeTolerance = 1;	/* how far inside our maximum range we should try to sit */
 			/* todo: choose the appropriate weapon, when only one works against this target */
-			var weapon = info.PrimaryWeapon ?? info.SecondaryWeapon;
+			var weapon = self.GetPrimaryWeapon() ?? self.GetSecondaryWeapon();
 
 			self.QueueActivity(new Activities.Attack(order.TargetActor,
-					Math.Max(0, (int)Rules.WeaponInfo[weapon].Range - RangeTolerance)));
+					Math.Max(0, (int)weapon.Range - RangeTolerance)));
 		}
 	}
 }

OpenRa.Game/Traits/Util.cs

@@ -146,9 +146,8 @@ namespace OpenRa.Game.Traits
 		public static float GetMaximumRange(Actor self)
 		{
 			var info = self.Info.Traits.WithInterface<AttackBaseInfo>().First();
-			return new[] { info.PrimaryWeapon, info.SecondaryWeapon }
+			return new[] { self.GetPrimaryWeapon(), self.GetSecondaryWeapon() }
-				.Where(w => w != null)
+				.Where(w => w != null).Max(w => w.Range);
-				.Max(w => Rules.WeaponInfo[w].Range);
 		}
 	}
 }