clean up after players who left

init.lua

@@ -1,4 +1,3 @@
-local player_waypoints = {}
 local update_interval = 1.31415
 local compass_precision = 10 -- set to 1 to show whole number or 10 for 1 decimal
 local default_waypoint_color = 0xFFFFFF
@@ -7,10 +6,10 @@ local point_to_objects = false -- unimplemented
 local point_to_liquids = true
 local compass_range = 180
 
--- lua metatables? what is that? :P
--- local function get_compass_meta_id(meta)
---     return meta:get_string("waypoint_compass:id") ~= "" or "default_id"
--- end
+
+-- internal mod state
+local player_waypoints = {} -- store a current player waypoint to see if it needs to be updated
+local compass_dialog_context = {} -- store a compass item that player is editing via dialog
 
 
 local function set_compass_meta_label(meta, label)
@@ -188,6 +187,16 @@ minetest.register_globalstep(function(dtime)
 end)
 
 
+minetest.register_on_leaveplayer(function(player, timed_out)
+        local player_name = player:get_player_name()
+        if player_name ~= "" then
+            -- delete info about players that are left
+            player_waypoints[player_name] = nil
+            compass_dialog_context[player_name] = nil
+        end
+end)
+
+
 local function coords_to_string(pos)
     -- strip "()"
     if not pos then
@@ -210,8 +219,6 @@ local function coords_from_string(str)
 end
 
 
-local compass_dialog_context = {}
-
 local function show_basic_dialog(itemstack, player)
     local meta = itemstack:get_meta()
     -- set focus to "close" button to preven accidental edting