Fix terrain positions for targets not being serialized for Orders

OpenRA.Game/Network/Order.cs

@@ -156,7 +156,18 @@ public static Order Deserialize(World world, BinaryReader r)
 									else
 									{
 										var pos = new WPos(r.ReadInt32(), r.ReadInt32(), r.ReadInt32());
-										target = Target.FromPos(pos);
+
+										var numberOfTerrainPositions = r.ReadInt16();
+										if (numberOfTerrainPositions == -1)
+											target = Target.FromPos(pos);
+										else
+										{
+											var terrainPositions = new WPos[numberOfTerrainPositions];
+											for (var i = 0; i < numberOfTerrainPositions; i++)
+												terrainPositions[i] = new WPos(r.ReadInt32(), r.ReadInt32(), r.ReadInt32());
+
+											target = Target.FromSerializedTerrainPosition(pos, terrainPositions);
+										}
 									}
 
 									break;
@@ -388,6 +399,21 @@ public byte[] Serialize()
 									w.Write(targetState.Pos.X);
 									w.Write(targetState.Pos.Y);
 									w.Write(targetState.Pos.Z);
+
+									// Don't send extra data over the network that will be restored by the Target ctor
+									var terrainPositions = targetState.TerrainPositions.Length;
+									if (terrainPositions == 1 && targetState.TerrainPositions[0] == targetState.Pos)
+										w.Write((short)-1);
+									else
+									{
+										w.Write((short)terrainPositions);
+										foreach (var position in targetState.TerrainPositions)
+										{
+											w.Write(position.X);
+											w.Write(position.Y);
+											w.Write(position.Z);
+										}
+									}
 								}
 
 								break;

OpenRA.Game/Server/ProtocolVersion.cs

@@ -77,6 +77,6 @@ public static class ProtocolVersion
 		// The protocol for server and world orders
 		// This applies after the handshake has completed, and is provided to support
 		// alternative server implementations that wish to support multiple versions in parallel
-		public const int Orders = 20;
+		public const int Orders = 21;
 	}
 }

OpenRA.Game/Traits/Target.cs

@@ -288,7 +288,8 @@ public override bool Equals(object other)
 
 		// Expose internal state for serialization by the orders code *only*
 		internal static Target FromSerializedActor(Actor a, int generation) { return a != null ? new Target(a, generation) : Invalid; }
-		internal (TargetType Type, Actor Actor, int Generation, CPos? Cell, SubCell? SubCell, WPos Pos) SerializableState =>
-			(type, Actor, generation, cell, subCell, terrainCenterPosition);
+		internal static Target FromSerializedTerrainPosition(WPos centerPosition, WPos[] terrainPositions) { return new Target(centerPosition, terrainPositions); }
+		internal (TargetType Type, Actor Actor, int Generation, CPos? Cell, SubCell? SubCell, WPos Pos, WPos[] TerrainPositions) SerializableState =>
+			(type, Actor, generation, cell, subCell, terrainCenterPosition, terrainPositions);
 	}
 }