Do not duplicate definitions of 'print' in every file

advtrains/couple.lua

@@ -9,7 +9,6 @@ wagon
 
 wagons keep their couple entity minetest-internal id inside the field discouple_id. if it refers to nowhere, they will spawn a new one if player is near
 ]]
-local print=function(t, ...) minetest.log("action", table.concat({t, ...}, " ")) minetest.chat_send_all(table.concat({t, ...}, " ")) end
 
 
 minetest.register_entity("advtrains:discouple", {

advtrains/init.lua

@@ -4,10 +4,8 @@ advtrains={}
 
 advtrains.modpath = minetest.get_modpath("advtrains")
 
---print=function(text)
---	minetest.log("action", tostring(text) or "<non-string>")
---end
-print = function(t) minetest.log("action", t) minetest.chat_send_all(t) end
+print=function(t, ...) minetest.log("action", table.concat({t, ...}, " ")) minetest.chat_send_all(table.concat({t, ...}, " ")) end
+sid=function(id) return string.sub(id, -4) end
 
 dofile(advtrains.modpath.."/helpers.lua");
 dofile(advtrains.modpath.."/debugitems.lua");

advtrains/tracks.lua

@@ -386,7 +386,7 @@ advtrains.detector.clean_step_before = false
 --The entry already being contained in advtrains.detector.on_node_restore will not trigger an on_train_enter event on the node.  (when path is reset, this is saved).
 function advtrains.detector.enter_node(pos, train_id)
 	local pts = minetest.pos_to_string(advtrains.round_vector_floor_y(pos))
-	--print("enterNode "..pts.." "..train_id)
+	print("enterNode "..pts.." "..sid(train_id))
 	if not advtrains.detector.on_node[pts] then
 		advtrains.detector.on_node[pts]=train_id
 		if advtrains.detector.on_node_restore[pts] then
@@ -394,14 +394,18 @@ function advtrains.detector.enter_node(pos, train_id)
 		else
 			advtrains.detector.call_enter_callback(advtrains.round_vector_floor_y(pos), train_id)
 		end
+	else
+		print(""..pts.." already occupied")
 	end
 end
 function advtrains.detector.leave_node(pos, train_id)
 	local pts = minetest.pos_to_string(advtrains.round_vector_floor_y(pos))
-	--print("leaveNode "..pts.." "..train_id)
-	if advtrains.detector.on_node[pts] then
+	print("leaveNode "..pts.." "..sid(train_id))
+	if advtrains.detector.on_node[pts] and advtrains.detector.on_node[pts]==train_id then
 		advtrains.detector.call_leave_callback(advtrains.round_vector_floor_y(pos), train_id)
 		advtrains.detector.on_node[pts]=nil
+	else
+		print(""..pts.." occupied by another train")
 	end
 end
 --called immediately before invalidating paths

advtrains/trainlogic.lua

@@ -1,12 +1,8 @@
 --trainlogic.lua
 --controls train entities stuff about connecting/disconnecting/colliding trains and other things
 
-local print=function(t, ...) minetest.log("action", table.concat({t, ...}, " ")) minetest.chat_send_all(table.concat({t, ...}, " ")) end
-local sid=function(id) return string.sub(id, -4) end
---local print=function() end
 
 local benchmark=false
---printbm=function(str, t) print("[advtrains]"..str.." "..((os.clock()-t)*1000).."ms") end
 local bm={}
 local bmlt=0
 local bmsteps=0