[assign-minecarts] handle case where minecart is assigned but is missing

assign-minecarts.lua

@@ -2,6 +2,7 @@
 --@ module = true
 
 local argparse = require('argparse')
+local utils = require('utils')
 
 function get_free_vehicles()
     local free_vehicles = {}
@@ -13,16 +14,12 @@ function get_free_vehicles()
     return free_vehicles
 end
 
-local function has_minecart(route)
-    return #route.vehicle_ids > 0
-end
-
 local function has_stops(route)
     return #route.stops > 0
 end
 
 local function get_minecart(route)
-    if not has_minecart(route) then return end
+    if #route.vehicle_ids == 0 then return end
     local vehicle = utils.binsearch(df.global.world.vehicles.active, route.vehicle_ids[0], 'id')
     if not vehicle then return end
     return df.item.find(vehicle.item_id)
@@ -37,8 +34,9 @@ local function get_id_and_name(route)
 end
 
 local function assign_minecart_to_route(route, quiet, minecart)
-    if has_minecart(route) then
-        return get_minecart(route)
+    local assigned_minecart = get_minecart(route)
+    if assigned_minecart then
+        return assigned_minecart
     end
     if not has_stops(route) then
         if not quiet then
@@ -57,6 +55,12 @@ local function assign_minecart_to_route(route, quiet, minecart)
             return false
         end
     end
+    for _,vehicle_id in ipairs(route.vehicle_ids) do
+        local vehicle = utils.binsearch(df.global.world.vehicles.all, vehicle_id, 'id')
+        if vehicle then vehicle.route_id = -1 end
+    end
+    route.vehicle_ids:resize(0)
+    route.vehicle_stops:resize(0)
     route.vehicle_ids:insert('#', minecart.id)
     route.vehicle_stops:insert('#', 0)
     minecart.route_id = route.id
@@ -99,7 +103,7 @@ local function list()
         for _,route in ipairs(routes) do
             print(('%-8d  %-9s  %-9s  %s')
                   :format(route.id,
-                          has_minecart(route) and 'yes' or 'NO',
+                          get_minecart(route) and 'yes' or 'NO',
                           has_stops(route) and 'yes' or 'NO',
                           get_name(route)))
         end
@@ -113,7 +117,7 @@ local function all(quiet)
     local minecarts, idx = get_free_vehicles(), 1
     local routes = df.global.plotinfo.hauling.routes
     for _,route in ipairs(routes) do
-        if has_minecart(route) then
+        if get_minecart(route) then
             goto continue
         end
         if not assign_minecart_to_route(route, quiet, minecarts[idx]) then
@@ -148,7 +152,7 @@ local function main(args)
         local route = get_route_by_id(requested_route_id)
         if not route then
             dfhack.printerr('route id not found: '..requested_route_id)
-        elseif has_minecart(route) then
+        elseif get_minecart(route) then
             if not quiet then
                 print(('Route %s already has a minecart assigned.')
                     :format(get_id_and_name(route)))

changelog.txt

@@ -53,6 +53,7 @@ Template for new versions:
 - `gui/sitemap`: show whether a unit is caged
 - `gui/control-panel`: include option for turning off dumping of old clothes for `tailor`, for players who have magma pit dumps and want to save old clothes from being dumped into the magma
 - `position`: report current historical era (e.g., "Age of Myth"), site/adventurer world coords, and mouse map tile coords
+- `assign-minecarts`: reassign vehicles to routes where the vehicle has been destroyed (or has otherwise gone missing)
 
 ## Documentation
 - `gui/embark-anywhere`: add information about how the game determines world tile pathability and instructions for bridging two landmasses