Re-add debug ring buffer and print its contents on a lua crash

When the crash on linuxworks has been fixed, the ringbuffer will go into master and behind an option
also fix last commit

advtrains/advtrains/debugringbuffer.lua

@@ -0,0 +1,44 @@
+--so, some ringbuffers one for each train
+
+local ringbuflen=1000
+
+local ringbufs={}
+local ringbufcnt={}
+
+function advtrains.drb_record(tid, msg)
+	if not ringbufs[tid] then
+		ringbufs[tid]={}
+		ringbufcnt[tid]=0
+	end
+	ringbufs[tid][ringbufcnt[tid]]=msg
+	ringbufcnt[tid]=ringbufcnt[tid]+1
+	if ringbufcnt[tid] > ringbuflen then
+		ringbufcnt[tid]=0
+	end
+end
+function advtrains.drb_dump(tid)
+	atlog("Debug ring buffer output for '"..tid.."':")
+	local stopcnt=ringbufcnt[tid]
+	if not stopcnt then
+		atlog("ID unknown!")
+		return
+	end
+	repeat
+		atlog(ringbufs[tid][ringbufcnt[tid]])
+		ringbufcnt[tid]=ringbufcnt[tid]+1
+		if ringbufcnt[tid] > ringbuflen then
+			ringbufcnt[tid]=0
+		end
+	until ringbufcnt[tid]==stopcnt
+end
+
+minetest.register_chatcommand("atdebug_show",
+	{
+        params = "train sid", -- Short parameter description
+        description = "Dump debug log", -- Full description
+        privs = {train_operator=true}, -- Require the "privs" privilege to run
+        func = function(name, param)
+			advtrains.drb_dump(param)
+        end, -- Called when command is run.
+                                      -- Returns boolean success and text output.
+    })

advtrains/advtrains/helpers.lua

@@ -170,6 +170,19 @@ function advtrains.minAngleDiffRad(r1, r2)
 		return try3
 	end
 end
+
+function advtrains.dumppath(path)
+	atlog("Dumping a path:")
+	if not path then atlog("dumppath: no path(nil)") return end
+	local temp_path={}
+	for ipt, iit in pairs(path) do 
+		temp_path[#temp_path+1]={i=ipt, p=iit}
+	end
+	table.sort(temp_path, function (k1, k2) return k1.i < k2.i end)
+	for _,pit in ipairs(temp_path) do
+		atlog(pit.i.." > "..minetest.pos_to_string(pit.p))
+	end
+end
 
 function advtrains.merge_tables(a, ...)
 	local new={}

advtrains/advtrains/init.lua

@@ -15,6 +15,13 @@ function advtrains.pcall(fun)
 	if no_action then return end
 	
 	local succ, return1, return2, return3, return4=xpcall(fun, function(err)
+			if advtrains.atprint_context_tid then
+				local train=advtrains.trains[advtrains.atprint_context_tid_full]
+				advtrains.dumppath(train.path)
+				atwarn("Dumping last debug outputs: ", err)
+				atprint("Train state: index",train.index,"end_index", train.end_index,"| max_iot", train.max_index_on_track, "min_iot", train.min_index_on_track, "<> pe_min", train.path_extent_min,"pe_max", train.path_extent_max)
+				advtrains.drb_dump(advtrains.atprint_context_tid)
+			end
 			atwarn("Lua Error occured: ", err)
 			atwarn(debug.traceback())
 		end)
@@ -72,7 +79,12 @@ function advtrains.print_concat_table(a)
 	return str
 end
 
-atprint=function() end
+atprint=function(t, ...)
+	local context=advtrains.atprint_context_tid
+	if not context then return end
+	local text=advtrains.print_concat_table({t, ...})
+	advtrains.drb_record(context, text)
+end
 atlog=function(t, ...)
 	local context=advtrains.atprint_context_tid
 	if not context then return end
@@ -104,6 +116,8 @@ advtrains.meseconrules =
  {x=0,  y=-1, z=-1},
  {x=0, y=-2, z=0}}
  
+
+dofile(advtrains.modpath.."/debugringbuffer.lua")
  
 dofile(advtrains.modpath.."/trainlogic.lua")
 dofile(advtrains.modpath.."/trainhud.lua")
@@ -260,9 +274,12 @@ end
 local init_load=false
 local save_interval=20
 local save_timer=save_interval
+advtrains.mainloop_runcnt=0
 
 minetest.register_globalstep(function(dtime_mt)
 	return advtrains.pcall(function()
+		advtrains.mainloop_runcnt=advtrains.mainloop_runcnt+1
+		atprint("Running the main loop, runcnt",advtrains.mainloop_runcnt)
 		--call load once. see advtrains.load() comment
 		if not init_load then
 			advtrains.load()

advtrains/advtrains/nodedb.lua

@@ -286,7 +286,7 @@ local ptime=0
 minetest.register_chatcommand("at_restore_ndb",
 	{
         params = "", -- Short parameter description
-        description = "Write node db back to map", -- Full description
+        description = "Write node db back to map and find ghost nodes", -- Full description
         privs = {train_operator=true, worldedit=true}, -- Require the "privs" privilege to run
         func = function(name, param)
 			return advtrains.pcall(function()
@@ -298,5 +298,9 @@ minetest.register_chatcommand("at_restore_ndb",
 				return true
 			end)
         end,
+        privs = {train_operator=true}, -- Require the "privs" privilege to run
+        func = function(name, param)
+			ndb.restore_all()
+        end, -- Called when command is run.
     })
 

advtrains/advtrains/trainlogic.lua

@@ -56,14 +56,17 @@ advtrains.mainloop_trainlogic=function(dtime)
 	advtrains.detector.on_node={}
 	for k,v in pairs(advtrains.trains) do
 		advtrains.atprint_context_tid=sid(k)
+		advtrains.atprint_context_tid_full=k
 		advtrains.train_step_a(k, v, dtime)
 	end
 	for k,v in pairs(advtrains.trains) do
 		advtrains.atprint_context_tid=sid(k)
+		advtrains.atprint_context_tid_full=k
 		advtrains.train_step_b(k, v, dtime)
 	end
 	
 	advtrains.atprint_context_tid=nil
+	advtrains.atprint_context_tid_full=nil
 	
 	atprintbm("trainsteps", t)
 	endstep()
@@ -131,6 +134,10 @@ train step structure:
 ]]
 
 function advtrains.train_step_a(id, train, dtime)
+	atprint("--- runcnt ",advtrains.mainloop_runcnt,": index",train.index,"end_index", train.end_index,"| max_iot", train.max_index_on_track, "min_iot", train.min_index_on_track, "<> pe_min", train.path_extent_min,"pe_max", train.path_extent_max)
+	if train.min_index_on_track then
+		assert(math.floor(train.min_index_on_track)==train.min_index_on_track)
+	end
 	--- 1. LEGACY STUFF ---
 	if not train.drives_on or not train.max_speed then
 		advtrains.update_trainpart_properties(id)
@@ -235,6 +242,7 @@ function advtrains.train_step_a(id, train, dtime)
 	local t_info, train_pos=sid(id), train.path[math.floor(train.index)]
 	if train_pos then
 		t_info=t_info.." @"..minetest.pos_to_string(train_pos)
+		--atprint("train_pos:",train_pos)
 	end
 	
 	--apply off-track handling:

advtrains/advtrains/wagons.lua

@@ -286,7 +286,7 @@ function wagon:on_step(dtime)
 		--check infotext
 		local outside=self:train().text_outside or ""
 		if self.object:get_properties().infotext~=outside then
-			self.object:set_properties({infotext=outside})
+			self.object:set_properties({infotext=sid(self.train_id)})
 		end
 		
 		local gp=self:train()