fix connecting multiple pipes to the refinery drain

planet/Objects.ocd/Items.ocd/Tools.ocd/Pipe.ocd/Script.c

@@ -254,7 +254,8 @@ public func AddLineConnectionTo(object target, bool block_cutting)
 			line->SwitchConnection(this, target);
 			SetPipeLine(line);
 			line.BlockPipeCutting = block_cutting;
-			ScheduleCall(this, this.Enter, 1, nil, line); // delayed entrance, so that the message is still displayed above the clonk
+			// Delayed entrance, so that the message is still displayed above the clonk.
+			ScheduleCall(this, this.Enter, 1, nil, line);
 			return line;
 		}
 		else
@@ -349,7 +350,7 @@ public func Report(string message)
 	var reporter = this;
 	var next = Contained();
 	
-	while(next)
+	while (next)
 	{
 		reporter = next;
 		next = reporter->Contained();

planet/Objects.ocd/Libraries.ocd/LiquidControl.ocd/LiquidTank.ocd/Script.c

@@ -243,8 +243,16 @@ public func DoSwapSourceDrain(object source, object drain)
 public func FindAvailablePipe(object container, find_state)
 {
 	for (var pipe in FindObjects(Find_ID(Pipe), Find_Container(container), find_state))
-		if (!this->~QueryConnectPipe(pipe, false))
-			return pipe;
+	{
+		if (this->~QueryConnectPipe(pipe, false))
+			continue;
+		// Because of the delayed entrance into the pipeline of 1 frame the pipe may still be considered available.
+		// Therefore check also there there exists no connection of the line to this object.
+		var line = pipe->GetConnectedLine();
+		if (line && line->IsConnectedTo(this, true))
+			continue;
+		return pipe;		
+	}
 	return nil;
 }
 

planet/Worlds.ocf/RapidRefining.ocs/RefineryDrain.ocd/Script.c

@@ -25,7 +25,14 @@ public func IsLiquidContainerForMaterial(string liquid)
 public func QueryConnectPipe(object pipe, bool do_msg)
 {
 	if (pipe->IsDrainPipe() || pipe->IsNeutralPipe())
-		return false;
+	{
+		// Also check if already connected to this refinery drain.
+		var line = pipe->GetConnectedLine();
+		if (!line)
+			return false;		
+		if (!line->IsConnectedTo(this, true))
+			return false;
+	}
 	if (do_msg)
 		pipe->Report("$MsgPipeProhibited$");
 	return true;
@@ -33,10 +40,26 @@ public func QueryConnectPipe(object pipe, bool do_msg)
 
 public func OnPipeConnect(object pipe, string specific_pipe_state)
 {
-	SetNeutralPipe(pipe);
+	SetDrainPipe(pipe);
+	pipe->SetDrainPipe();
 	pipe->Report("$MsgConnectedPipe$");
 }
 
+public func OnPipeDisconnect(object pipe)
+{
+	var result = inherited(pipe, ...);
+	// There may be still drain pipes connected, selected one as the current drain pipe.
+	for (var line in FindObjects(Find_Func("IsConnectedTo", this)))
+	{
+		var new_pipe = line->GetPipeKit();
+		if (new_pipe == pipe || !new_pipe->IsDrainPipe())
+			continue;
+		SetDrainPipe(new_pipe);
+		break;
+	}
+	return result;
+}
+
 
 /*-- Interaction Interface --*/