9 files changed, 350 insertions, 112 deletions
diff --git a/advtrains/track_reg_helper.lua b/advtrains/track_reg_helper.lua
index 31741d6..e2f71e8 100644
--- a/advtrains/track_reg_helper.lua
+++ b/advtrains/track_reg_helper.lua
@@ -484,6 +484,11 @@ local function append_statemap_suffix(state_map, nnpref, rot)
 	return t
 end
 
+function advtrains.default_suitable_substrate(upos)
+	return core.registered_nodes[core.get_node(upos).name]
+		and core.registered_nodes[core.get_node(upos).name].walkable
+end
+
 function advtrains.register_tracks(tracktype, def, preset)
 	if not preset.v25_format then
 		error("advtrains.register_tracks(): A track preset for pre-v2.5 is used with advtrains 2.5+. Mod probably defines own track preset instead of using it from the advtrains.ap table! Please check track mod compatibility!")
@@ -509,8 +514,7 @@ function advtrains.register_tracks(tracktype, def, preset)
 						return itemstack, false
 					end
 					if minetest.registered_nodes[minetest.get_node(pos).name] and minetest.registered_nodes[minetest.get_node(pos).name].buildable_to then
-						local s = minetest.registered_nodes[minetest.get_node(upos).name] and minetest.registered_nodes[minetest.get_node(upos).name].walkable
-						if s then
+						if (def.suitable_substrate and def.suitable_substrate or advtrains.default_suitable_substrate)(upos) then
 	--						minetest.chat_send_all(nnprefix)
 							local yaw = placer:get_look_horizontal()
 							advtrains.trackplacer.place_track(pos, nnprefix, name, yaw)
diff --git a/advtrains_interlocking/ars.lua b/advtrains_interlocking/ars.lua
index eb10497..5182cd3 100644
--- a/advtrains_interlocking/ars.lua
+++ b/advtrains_interlocking/ars.lua
@@ -3,26 +3,89 @@
 
 --[[
 	The "ARS table" and its effects:
-	Every route has (or can have) an associated ARS table. This can either be
-	ars = { [n] = {ln="<line>"}/{rc="<routingcode>"}/{c="<a comment>"} }
-	a list of rules involving either line or routingcode matchers (or comments, those are ignored)
-	The first matching rule determines the route to set.
-	- or -
-	ars = {default = true}
-	this means that all trains that no other rule matches on should use this route
+	Every route has (or can have) an associated ARS table:
+	ars = {
+		[n] = {
+			ln = "<line>"			-- either line
+			rc = "<routingcode>"  -- or routingcode
+			n = true/false -- true = logical not (matches everything that does not have this line/rc)
+			conj = { -- and conjunction, optional. This must be true in addition to the main rule
+				ln=... / rc=... / n=... -- like toplevel
+				conj=... -- can be nested
+						-- note that conj cannot have prio, in inherits the prio from main rule
+			}
+			prio = <num> -- optional, a priority number. If set, enables "multi-ARS" where train can wait for multiple routes at once
+			-- or
+			c="<a comment>"
+		}
+		default = true -- Route is the default route for trains
+		default_prio -- optional, priority for multi-ars with default route
+		default_conj = {...} -- optional, conditions (conjunction) that need to be fulfilled for this to be considered default route
+	}
 	
-	Compound ("and") conjunctions are not supported (--TODO should they?)
+	In case a train matches the ARS rules of multiple routes, precedence is as follows:
+	1. train matches rules without priority in one or more routes -> first matching route is unconditionally set
+	2. train matches rules with priority in one or more routes -> all of the matching routes are set (multi-ars)
+			in the order given by priority, first available route is set
+	3. route is default=true, default_prio=nil and train matches default_conj (if present) -> first default route is set
+	4. one or more routes are default=true, with default_prio set,and train matches default_conj (if present)
+			-> all of the matching routes are set (multi-ars) in the order given by priority, first available route is set
 	
 	For editing, those tables are transformed into lines in a text area:
 	{ln=...} -> LN ...
 	{rc=...} -> RC ...
 	{c=...}  -> #...
 	{default=true} -> *
-	See also route_ui.lua
+	n -> ! (e.g. ln=..., n=true -> !LN ...)
+	prio -> <num> (e.g. ln=..., prio=1 -> 1 LN ...)
+	
+	conj -> goes on the next line, with an & prepended, e.g.:
+		{ln="S1", conj={rc="Left"}} ->
+		LN S1
+		& RC Left
+	
+	Example combining everything:
+	ars = {
+		[1] = {
+			ln = "S1"
+			n = true
+			prio = 4
+			conj = {
+				rc = "R4"
+			}
+		}
+		default = true
+		default_prio = 2
+		default_conj = {
+			rc = "R5"
+			n = true
+		}
+	} ->
+	4 !LN S1
+	& RC R4
+	2 *
+	& !RC R5
+	
 ]]
 
 local il = advtrains.interlocking
 
+
+local function conj_to_text(conj, txt)
+	while conj do
+		n = ""
+		if conj.n then
+			n = "!"
+		end
+		if conj.ln then
+			txt[#txt+1] = "& "..n.."LN "..conj.ln
+		elseif conj.rc then
+			txt[#txt+1] = "& "..n.."RC "..conj.rc
+		end
+		conj = conj.conj
+	end
+end
+
 -- The ARS data are saved in a table format, but are entered in text format. Utility functions to transform between both.
 function il.ars_to_text(arstab)
 	if not arstab then
@@ -32,103 +95,213 @@ function il.ars_to_text(arstab)
 	local txt = {}
 
 	for i, arsent in ipairs(arstab) do
+		local prio = ""
+		if arsent.prio then
+			prio = arsent.prio.." "
+		end
 		local n = ""
 		if arsent.n then
 			n = "!"
 		end
 		if arsent.ln then
-			txt[#txt+1] = n.."LN "..arsent.ln
+			txt[#txt+1] = prio..n.."LN "..arsent.ln
 		elseif arsent.rc then
-			txt[#txt+1] = n.."RC "..arsent.rc
+			txt[#txt+1] = prio..n.."RC "..arsent.rc
 		elseif arsent.c then
 			txt[#txt+1] = "#"..arsent.c
 		end
+		conj_to_text(arsent.conj, txt)
 	end
 	
 	if arstab.default then
-		return "*\n" .. table.concat(txt, "\n")
+		local prio = ""
+		if arstab.default_prio then
+			prio = arstab.default_prio.." "
+		end
+		txt[#txt+1] = prio.."*"
+		conj_to_text(arstab.default_conj, txt)
 	end
 	return table.concat(txt, "\n")
 end
 
+local function parse_ruleexp(line)
+	local excl, key, val = string.match(line, "^%s*(!?)%s*([RL][CN])%s+(.+)%s*$")
+	if key == "RC" then
+		return {rc=val, n=(excl=="!")}
+	elseif key == "LN" then
+		return {ln=val, n=(excl=="!")}
+	end
+end
+
 function il.text_to_ars(t)
 	if not string.match(t, "%S+") then
 		return nil
-	elseif t=="*" then
-		return {default=true}
 	end
 	local arstab = {}
+	local previtem
 	for line in string.gmatch(t, "[^\r\n]+") do
-		if line=="*" then
-			arstab.default = true
+		-- a) comment
+		local ct = string.match(line, "^#(.*)$")
+		if ct then
+			arstab[#arstab+1] = {c = ct}
+			previtem = nil
 		else
-			local c, v = string.match(line, "^(...?)%s(.*)$")
-			if c and v then
-				local n = nil
-				if string.sub(c,1,1) == "!" then
-					n = true
-					c = string.sub(c,2)
-				end
-				local tt=string.upper(c)
-				if tt=="LN" then
-					arstab[#arstab+1] = {ln=v, n=n}
-				elseif tt=="RC" then
-					arstab[#arstab+1] = {rc=v, n=n}
+			-- b) Conjunction to the previous item
+			local conline = string.match(line, "^%s*&(.+)$")
+			if conline then
+				local conj = parse_ruleexp(conline)
+				if conj and previtem==true then
+					-- previtem was default
+					arstab.default_conj = conj
+					previtem = conj
+				elseif conj and previtem then
+					previtem.conj = conj
+					previtem = conj
+				else
+					-- dont know what to do with line, put as comment
+					arstab[#arstab+1] = {c = "? "..line}
+					previtem = nil
 				end
 			else
-				local ct = string.match(line, "^#(.*)$")
-				if ct then arstab[#arstab+1] = {c = ct} end
+				-- c) Normal rule spec
+				local prio, ruleline = string.match(line, "^%s*([0-9]*)%s*(.+)%s*$")
+				if ruleline == "*" then
+					-- ruleline is the asterisk, this is default
+					arstab.default = true
+					arstab.default_prio = tonumber(prio) -- evals to nil if not given
+					previtem = true -- marks that previtem was asterisk
+				elseif ruleline then
+					-- ruleline is present, parse it
+					local rule = parse_ruleexp(ruleline)
+					if not rule then
+						-- dont know what to do with line, put as comment
+						arstab[#arstab+1] = {c = "? "..line}
+						previtem = nil
+					else
+						rule.prio = tonumber(prio) -- evals to nil if not given
+						arstab[#arstab+1] = rule
+						previtem = rule
+					end
+				else
+					-- d) nothing else works, save line as comment
+					arstab[#arstab+1] = {c = "? "..line}
+					previtem = nil
+				end
 			end
 		end
 	end
 	return arstab
 end
 
-local function find_rtematch(routes, train)
-	local default
-	for rteid, route in ipairs(routes) do
-		if route.ars then
-			if route.ars.default then
-				default = rteid
-			else
-				if il.ars_check_rule_match(route.ars, train) then
-					return rteid
-				end
-			end
+
+local function match_arsent(arsent, train)
+	local rule_matches = false
+	if arsent.ln then
+		local line = train.line
+		rule_matches = line and arsent.ln == line
+		if arsent.n then rule_matches = not rule_matches end
+	elseif arsent.rc then
+		local routingcode = train.routingcode
+		rule_matches = routingcode and string.find(" "..routingcode.." ", " "..arsent.rc.." ", nil, true)
+		if arsent.n then rule_matches = not rule_matches end
+	end
+	if rule_matches then
+		-- if the entry has a conjunction, go on checking
+		if arsent.conj then
+			return match_arsent(arsent.conj, train)
+		else
+			return true
 		end
+	else
+		return false
 	end
-	return default
 end
 
--- Checks whether ARS rule explicitly matches. This does not take into account the "default" field, since a wider context is required for this.
--- Returns the rule number that matched, or nil if nothing matched
+-- Given an ARS rule table, check whether any of the clauses in it match the train.
+-- Returns: match_specific, match_default
+--		match_specific: One of the clauses explicitly matched (if this is non-false, match_default is not checked and always given false)
+--		match_default: The default clause (*) matched (as well as any conjunctions attached to the default clause)
+--		both of these can be either true (unconditional match), a number (priority for multi-ars) or false
 function il.ars_check_rule_match(ars, train)
 		if not ars then
-			return nil
+			return nil, nil
 		end
-		local line = train.line
-		local routingcode = train.routingcode
 		for arskey, arsent in ipairs(ars) do
-			--atdebug(arsent, line, routingcode)
-			if arsent.n then
-				-- rule is inverse...
-				if arsent.ln and (not line or arsent.ln ~= line) then
-					return arskey
-				elseif arsent.rc and (not routingcode or not string.find(" "..routingcode.." ", " "..arsent.rc.." ", nil, true)) then
-					return arskey
-				end
-				return nil
+			local rule_matches = match_arsent(arsent, train)
+			if rule_matches then
+				return (arsent.prio or true), nil
 			end
-				
-			if arsent.ln and line and arsent.ln == line then
-				return arskey
-			elseif arsent.rc and routingcode and string.find(" "..routingcode.." ", " "..arsent.rc.." ", nil, true) then
-				return arskey
+		end
+		if ars.default then
+			local def_matches = true
+			if ars.default_conj then
+				def_matches = match_arsent(ars.default_conj, train)
 			end
+			if def_matches then
+				return false, (ars.default_prio or true)
+			end
+		end
+		return false,false
+end
+
+local function sort_priority(sprio)
+	-- insertion sort
+	local order = {}
+	local oprio = {}
+	for rteid, prio in pairs(sprio) do
+		local inspos = 1
+		while order[inspos] do
+			if oprio[inspos] > prio then
+				-- next item has higher priority number (= less urgent), insert before it
+				break
+			elseif oprio[inspos] == prio and order[inspos] > rteid then
+				-- next item has same priority as current and a higher routeid, insert before it
+				break
+			end
+			inspos = inspos + 1
 		end
+		table.insert(order, inspos, rteid)
+		table.insert(oprio, inspos, prio)
+	end
+	--atdebug("sort_priority",sprio,"result",order,oprio)
+	if #order == 1 then
+		return order[1] -- only one route, table doesnt make sense
+	end
+	return order
+end
+
+local function find_rtematch(routes, train)
+	local sprio = {}
+	local default = nil
+	local dprio = {}
+	for rteid, route in ipairs(routes) do
+		if route.ars then
+			local mspec, mdefault = il.ars_check_rule_match(route.ars, train)
+			--atdebug("route",rteid,"ars",route.ars,"gives", mspec, mdefault)
+			if mspec == true then
+				return rteid
+			elseif mspec then
+				sprio[rteid] = mspec
+			end
+			if mdefault == true then
+				if not default then default = rteid end
+			elseif mdefault then
+				dprio[rteid] = mdefault
+			end
+		end
+	end
+	if next(sprio) then
+		return sort_priority(sprio)
+	elseif default then
+		return default
+	elseif next(dprio) then
+		return sort_priority(dprio)
+	else
 		return nil
+	end
 end
 
+
 function advtrains.interlocking.ars_check(signalpos, train, trig_from_dst)
 	-- check for distant signal
 	-- this whole check must be delayed until after the route setting has taken place, 
@@ -169,6 +342,7 @@ function advtrains.interlocking.ars_check(signalpos, train, trig_from_dst)
 		
 		local rteid = find_rtematch(tcbs.routes, train)
 		if rteid then
+			--atdebug("Ars setting ",rteid)
 			--delay routesetting, it should not occur inside train step
 			-- using after here is OK because that gets called on every path recalculation
 			minetest.after(0, il.route.update_route, sigd, tcbs, rteid, nil)
diff --git a/advtrains_interlocking/database.lua b/advtrains_interlocking/database.lua
index 844d350..5e35dba 100644
--- a/advtrains_interlocking/database.lua
+++ b/advtrains_interlocking/database.lua
@@ -214,10 +214,11 @@ TCB data structure
 	-- aspect will be set accordingly.
 	routeset = <index in routes> -- Route set from this signal. This is the entry that is cleared once
 	-- train has passed the signal. (which will set the aspect to "danger" again)
-	route_committed = <boolean> -- When setting/requesting a route, routetar will be set accordingly,
+	-- routeset may be a table (e.g. {1,2}) while the route is not committed yet, indicating a wait for multiple routes at once (Multi-ARS)
+	route_committed = <boolean> -- When setting/requesting a route, routeset will be set accordingly,
 	-- while the signal still displays danger and nothing is written to the TCs
 	-- As soon as the route can actually be set, all relevant TCs and turnouts are set and this field
-	-- is set true, clearing the signal
+	-- is set true, clearing the signal (when this is true, routeset is never a table)
 	aspect = <asp> -- The aspect the signal should show. If this is nil, should show the most restrictive aspect (red)
 	signal_name = <string> -- The human-readable name of the signal, only for documenting purposes
 	routes = { <route definition> } -- a collection of routes from this signal
diff --git a/advtrains_interlocking/routesetting.lua b/advtrains_interlocking/routesetting.lua
index 1065cad..9901d23 100644
--- a/advtrains_interlocking/routesetting.lua
+++ b/advtrains_interlocking/routesetting.lua
@@ -363,7 +363,7 @@ end
 -- route setting
 -- Call this function to set and cancel routes!
 -- sigd, tcbs: self-explanatory
--- newrte: If a new route should be set, the route index of it (in tcbs.routes). nil otherwise
+-- newrte: If a new route should be set, the route index of it (in tcbs.routes). Can also be a table (multi-ars). nil otherwise
 -- cancel: true in combination with newrte=nil causes cancellation of the current route.
 function ilrs.update_route(sigd, tcbs, newrte, cancel)
 	--atdebug("Update_Route for",sigd,tcbs.signal_name)
@@ -390,37 +390,66 @@ function ilrs.update_route(sigd, tcbs, newrte, cancel)
 		if tcbs.route_committed then
 			return
 		end
-		if newrte then tcbs.routeset = newrte end
+		if newrte then
+			if type(newrte)=="table" and not next(newrte) then
+				error("update_route got multi-ARS with empty table, this is not allowed")
+			end
+			tcbs.routeset = newrte
+		else
+			if type(tcbs.routeset)=="table" and not next(tcbs.routeset) then
+				-- just unset, don't error
+				atwarn(sigd, "had multi-ARS route set with empty list! Cancelled!")
+				tcbs.routeset = nil
+				return
+			end
+		end
 		--atdebug("Setting:",tcbs.routeset)
-		local succ, rsn, cbts, cblk
-		local route = tcbs.routes[tcbs.routeset]
-		if route then
-			succ, rsn, cbts, cblk = ilrs.set_route(sigd, route)
+		-- check: single-ars or multi-ars?
+		local multi_rte
+		if type(tcbs.routeset) == "table" then
+			multi_rte = tcbs.routeset
 		else
-			succ = false
-			rsn = attrans("Route state changed.")
+			multi_rte = {tcbs.routeset}
 		end
-		if not succ then
-			tcbs.route_rsn = rsn
-			--atdebug("Routesetting failed:",rsn)
-			-- add cbts or cblk to callback table
-			if cbts then
-				--atdebug("cbts =",cbts)
-				if not ilrs.rte_callbacks.ts[cbts] then ilrs.rte_callbacks.ts[cbts]={} end
-				advtrains.insert_once(ilrs.rte_callbacks.ts[cbts], sigd, sigd_equal)
-			end
-			if cblk then
-				--atdebug("cblk =",cblk)
-				if not ilrs.rte_callbacks.lck[cblk] then ilrs.rte_callbacks.lck[cblk]={} end
-				advtrains.insert_once(ilrs.rte_callbacks.lck[cblk], sigd, sigd_equal)
+		for multi_idx, rteid in ipairs(multi_rte) do
+			local succ, rsn, cbts, cblk
+			local route = tcbs.routes[rteid]
+			if route then
+				succ, rsn, cbts, cblk = ilrs.set_route(sigd, route)
+			else
+				succ = false
+				rsn = attrans("Route with index @1 not found", rteid)
 			end
-		else
-			--atdebug("Committed Route:",tcbs.routeset)
-			-- set_route now sets the signal aspects
-			--has_changed_aspect = true
-			-- route success. apply default_autoworking flag if requested
-			if route.default_autoworking then
-				tcbs.route_auto = true --FIX 2025-01-08: never set it to false if it was true!
+			if not succ then
+				if multi_idx==1 then
+					tcbs.route_rsn = rsn
+				else
+					tcbs.route_rsn = (tcbs.route_rsn or "").."\n"..rsn
+				end
+				--atdebug("Routesetting",rteid,"failed:",rsn,"(multi-idx",multi_idx,")")
+				-- add cbts or cblk to callback table
+				if cbts then
+					--atdebug("cbts =",cbts)
+					if not ilrs.rte_callbacks.ts[cbts] then ilrs.rte_callbacks.ts[cbts]={} end
+					advtrains.insert_once(ilrs.rte_callbacks.ts[cbts], sigd, sigd_equal)
+				end
+				if cblk then
+					--atdebug("cblk =",cblk)
+					if not ilrs.rte_callbacks.lck[cblk] then ilrs.rte_callbacks.lck[cblk]={} end
+					advtrains.insert_once(ilrs.rte_callbacks.lck[cblk], sigd, sigd_equal)
+				end
+			else
+				--atdebug("Committed Route:",rteid,"(multi-idx",multi_idx,")")
+				-- replace multi_route by single actually committed route
+				tcbs.routeset = rteid
+				-- set_route now sets the signal aspects
+				--has_changed_aspect = true
+				-- route success. apply default_autoworking flag if requested
+				if route.default_autoworking then
+					tcbs.route_auto = true --FIX 2025-01-08: never set it to false if it was true!
+				end
+				-- break out of the for loop, dont try any more routes
+				break
 			end
 		end
 	end
diff --git a/advtrains_interlocking/signal_aspect_ui.lua b/advtrains_interlocking/signal_aspect_ui.lua
index 98a332a..49e7d8b 100644
--- a/advtrains_interlocking/signal_aspect_ui.lua
+++ b/advtrains_interlocking/signal_aspect_ui.lua
@@ -247,7 +247,9 @@ minetest.register_on_punchnode(function(pos, node, player, pointed_thing)
 					ipmarker(pos, plconnid)
 					minetest.chat_send_player(pname, "Configuring Signal: Successfully set influence point")
 					-- Try to find a TCB ahead and auto assign this signal there
-					if advtrains.interlocking.signal.get_signal_cap_level(signalpos) >= 2 then
+					local pc = player:get_player_control()
+					local no_auto_assign = pc.aux1
+					if not no_auto_assign and advtrains.interlocking.signal.get_signal_cap_level(signalpos) >= 2 then
 						try_auto_assign_to_tcb(signalpos, pos, plconnid, pname)
 					end
 				else
diff --git a/advtrains_interlocking/tcb_ts_ui.lua b/advtrains_interlocking/tcb_ts_ui.lua
index 814a11a..0be943a 100755
--- a/advtrains_interlocking/tcb_ts_ui.lua
+++ b/advtrains_interlocking/tcb_ts_ui.lua
@@ -828,14 +828,29 @@ function advtrains.interlocking.show_signalling_form(sigd, pname, sel_rte, calle
 	form = form.."button[5.5,1.2;1,1;setname;Set]"
 	
 	if tcbs.routeset then
-		local rte = tcbs.routes[tcbs.routeset]
-		if not rte then
-			atwarn("Unknown route set from signal!")
-			tcbs.routeset = nil
-			return
+		if type(tcbs.routeset)=="table" then
+			local rtenames = {}
+			for midx,rteid in ipairs(tcbs.routeset) do
+				local rte = tcbs.routes[rteid]
+				if not rte then
+					atwarn("Unknown route set from signal!")
+					tcbs.routeset = nil
+					return
+				end
+				rtenames[midx] = rte.name
+			end
+			form = form.."label[0.5,2.5;Multiple routes are requested (first available is set):]"
+			form = form.."label[0.5,3.0;"..minetest.formspec_escape(table.concat(rtenames,", ")).."]"
+		else
+			local rte = tcbs.routes[tcbs.routeset]
+			if not rte then
+				atwarn("Unknown route set from signal!")
+				tcbs.routeset = nil
+				return
+			end
+			form = form.."label[0.5,2.5;A route is requested from this signal:]"
+			form = form.."label[0.5,3.0;"..minetest.formspec_escape(rte.name).."]"
 		end
-		form = form.."label[0.5,2.5;A route is requested from this signal:]"
-		form = form.."label[0.5,3.0;"..minetest.formspec_escape(rte.name).."]"
 		if tcbs.route_committed then
 			form = form.."label[0.5,3.5;Route has been set.]"
 		else
@@ -1000,9 +1015,7 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 			end
 		end
 		if tcbs.routeset and fields.cancelroute then
-			if tcbs.routes[tcbs.routeset] and tcbs.routes[tcbs.routeset].ars then
-				tcbs.ars_ignore_next = true
-			end
+			tcbs.ars_ignore_next = true
 			-- if route committed, cancel route ts info
 			ilrs.update_route(sigd, tcbs, nil, true)
 		end
diff --git a/advtrains_line_automation/stoprail.lua b/advtrains_line_automation/stoprail.lua
index 89f4a09..aa8dfdd 100644
--- a/advtrains_line_automation/stoprail.lua
+++ b/advtrains_line_automation/stoprail.lua
@@ -24,7 +24,8 @@ local function updatemeta(pos)
 end
 
 local door_dropdown = {L=1, R=2, C=3}
-local door_dropdown_rev = {Right="R", Left="L", Closed="C"}
+--local door_dropdown_rev = {Right="R", Left="L", Closed="C"} -- Code review : why are the value in an order different than the one in the dropdown box ?
+local door_dropdown_code = {"L", "R", "C"} -- switch to numerical index of selection : for conversion of the numerical index in the opening side selection dropdown box to the internal codification
 
 local function show_stoprailform(pos, player)
 	local pe = advtrains.encode_pos(pos)
@@ -60,7 +61,7 @@ local function show_stoprailform(pos, player)
 	form = form.."field[4.30,2.0;1.75,1;track;"..S("Track")..";"..minetest.formspec_escape(stdata.track).."]"
 	form = form.."field[6.05,2.0;1.75,1;wait;"..S("Stop Time")..";"..stdata.wait.."]"
 	form = form.."label[0.5,2.6;"..S("Door Side").."]"
-	form = form.."dropdown[0.51,3.0;2;doors;"..S("Left")..","..S("Right")..","..S("Closed")..";"..door_dropdown[stdata.doors].."]"
+	form = form.."dropdown[0.51,3.0;2;doors;"..S("Left")..","..S("Right")..","..S("Closed")..";"..door_dropdown[stdata.doors]..";true]" -- switch to numerical index of the selection
 	form = form.."checkbox[3.00,2.4;reverse;"..S("Reverse train")..";"..(stdata.reverse and "true" or "false").."]"
 	form = form.."checkbox[3.00,2.8;kick;"..S("Kick out passengers")..";"..(stdata.kick and "true" or "false").."]"
 	form = form.."checkbox[3.00,3.2;waitsig;"..S("Wait for signal to clear")..";"..(stdata.waitsig and "true" or "false").."]"
@@ -120,7 +121,7 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 			
 			-- dropdowns
 			if fields.doors then
-				stdata.doors = door_dropdown_rev[fields.doors] or "C"
+				stdata.doors = door_dropdown_code[tonumber(fields.doors)] or "C" -- switch to numerical index of selection; attention : fields.doors is string typed, needed to be converted to an integer typed index in door_dropdown_code table
 			end
 			
 			if fields.track then
diff --git a/advtrains_luaautomation/atc_rail.lua b/advtrains_luaautomation/atc_rail.lua
index dd26f51..c98f62b 100644
--- a/advtrains_luaautomation/atc_rail.lua
+++ b/advtrains_luaautomation/atc_rail.lua
@@ -62,7 +62,7 @@ function r.fire_event(pos, evtdata, appr_internal)
 			local new_id = advtrains.split_train_at_index(train, index)
 			if new_id then
 				minetest.after(1,advtrains.atc.train_set_command,advtrains.trains[new_id], cmd, atc_arrow)
-				return true
+				return new_id
 			end
 			return false
 		end,
@@ -73,7 +73,7 @@ function r.fire_event(pos, evtdata, appr_internal)
 			if new_id then
 				minetest.after(1,advtrains.atc.train_set_command,advtrains.trains[new_id], cmd, atc_arrow)
 			end
-			return fc or ""
+			return (fc or ""), new_id
 		end,
 		split_off_locomotive = function(cmd, len)
 			assertt(cmd, "string")
@@ -81,7 +81,8 @@ function r.fire_event(pos, evtdata, appr_internal)
 			local new_id, fc = advtrains.split_train_at_fc(train, true, len)
 			if new_id then
 				minetest.after(1,advtrains.atc.train_set_command,advtrains.trains[new_id], cmd, atc_arrow)
-			end						
+			end
+			return (fc or ""), new_id					
 		end,
 		train_length = function ()
 			if not train_id then return false end
diff --git a/advtrains_signals_japan/init.lua b/advtrains_signals_japan/init.lua
index 1140b6b..728a91f 100644
--- a/advtrains_signals_japan/init.lua
+++ b/advtrains_signals_japan/init.lua
@@ -15,6 +15,19 @@ local light_distant = light_purple
 local light_off = signal_face_texture
 
 do
+	local model_dir = core.get_modpath("advtrains_signals_japan") .. DIR_DELIM .. "models"
+	local function add_model(name, content)
+		local fn = "advtrains_signals_japan_" .. name
+		if core.features.dynamic_add_media_startup then
+			core.dynamic_add_media {
+				filename = fn,
+				filedata = content,
+			}
+		else
+			core.mkdir(model_dir)
+			core.safe_file_write(model_dir .. DIR_DELIM .. fn, content)
+		end
+	end
 	local model_path_prefix = table.concat({minetest.get_modpath("advtrains_signals_japan"), "models", "advtrains_signals_japan_"}, DIR_DELIM)
 
 	local function vertex(x, y, z)
@@ -122,7 +135,7 @@ do
 	pole_vertices = table.concat(pole_vertices, "\n")
 	pole_objdef = table.concat(pole_objdef, "\n")
 	pole_uv = table.concat(pole_uv, "\n")
-	minetest.safe_file_write(model_path_prefix .. "pole.obj", table.concat({pole_vertices, pole_uv, pole_objdef}, "\n"))
+	add_model("pole.obj", table.concat({pole_vertices, pole_uv, pole_objdef}, "\n"))
 
 	-- generate signals
 	for lightcount = 5, 6 do
@@ -231,7 +244,7 @@ do
 			face_vertices = table.concat(face_vertices, "\n")
 			face_uv = table.concat(face_uv, "\n")
 			face_objdef = table.concat(face_objdef, "\n")
-			minetest.safe_file_write(model_path_prefix .. lightcount .. "_" .. rotname .. ".obj", table.concat({
+			add_model(lightcount .. "_" .. rotname .. ".obj", table.concat({
 				pole_vertices,
 				face_vertices,
 				table.concat(light_vertices, "\n"),