Missions/Raid+TreasureHunt: Oil barrels are actually filled with oil and don't empty.

planet/Missions.ocf/Raid.ocs/Objects.c

@@ -418,13 +418,17 @@ func InitializeObjects()
 
 	var MetalBarrel001 = CreateObjectAbove(MetalBarrel, 395, 1271);
 	MetalBarrel001->SetColor(0xff000000);
+	MetalBarrel001->PutLiquid("Oil");
 	var MetalBarrel002 = CreateObject(MetalBarrel, 421, 1268);
 	MetalBarrel002->SetR(-104);
 	MetalBarrel002->SetColor(0xff000000);
+	MetalBarrel002->PutLiquid("Oil");
 	var MetalBarrel003 = CreateObjectAbove(MetalBarrel, 411, 1271);
 	MetalBarrel003->SetColor(0xff000000);
+	MetalBarrel003->PutLiquid("Oil");
 	var MetalBarrel004 = CreateObjectAbove(MetalBarrel, 385, 1271);
 	MetalBarrel004->SetColor(0xff000000);
+	MetalBarrel004->PutLiquid("Oil");
 
 	var PowderKeg001 = CreateObject(PowderKeg, 378, 1268);
 	PowderKeg001->SetR(99);

planet/Missions.ocf/Raid.ocs/System.ocg/OilBarrel.c

@@ -30,8 +30,16 @@ private func AcceptMaterial(int material)
 	return false;
 }
 
-// ..and can also not be emptied.
+// ...and can also not be emptied.
 public func RejectUse()
 {
 	return true;
 }
+
+// ...not even when it hits the ground
+public func Hit()
+{
+	this->PlayBarrelHitSound();
+}
+// (okay, you could still put it into a building and attach a pump)
+

planet/Missions.ocf/TreasureHunt.ocs/System.ocg/DlgDagobert.c

@@ -166,6 +166,7 @@ func Dlg_Dagobert_Gem2(object clonk)
 	{
 		barrel->SetXDir(-15);
 		barrel->SetYDir(-20);
+		barrel->PutLiquid("Oil");
 	}
 	g_got_oil = true;
 	if (g_goal) g_goal->OnTreasureSold();

planet/Missions.ocf/TreasureHunt.ocs/System.ocg/OilBarrel.c

@@ -1,5 +1,5 @@
 // Goal timer: Barrel has to be brought to the plane
-// Doesn't matter if container or not.
+// Doesn't matter if contained or not.
 
 #appendto MetalBarrel
 
@@ -19,3 +19,22 @@ private func CheckForPlane()
 	}
 }
 
+// The barrel is always full with oil and does not accept anything else.
+private func AcceptMaterial(int material)
+{
+	return false;
+}
+
+// ...and can also not be emptied.
+public func RejectUse()
+{
+	return true;
+}
+
+// ...not even when it hits the ground
+public func Hit()
+{
+	this->PlayBarrelHitSound();
+}
+// (okay, you could still put it into a building and attach a pump)
+