Update

42.13/media/lua/client/Landtrain/LandtrainTowSyncClient.lua

@@ -9,6 +9,28 @@ local function log(msg)
     print("[Landtrain][TowSyncClient] " .. tostring(msg))
 end
 
+local function isTrailerScriptName(scriptName)
+    if not scriptName then return false end
+    return string.find(string.lower(scriptName), "trailer", 1, true) ~= nil
+end
+
+local function shouldForceNotTowingScript(vehicle)
+    if not vehicle then return false end
+    local scriptName = vehicle:getScriptName()
+    return not isTrailerScriptName(scriptName)
+end
+
+local function restoreTrailerScriptIfNeeded(vehicle)
+    if not vehicle then return end
+    if vehicle:getScriptName() ~= "notTowingA_Trailer" then return end
+
+    local md = vehicle:getModData()
+    local originalScript = md and md.towBarOriginalScriptName or nil
+    if originalScript and isTrailerScriptName(originalScript) then
+        vehicle:setScriptName(originalScript)
+    end
+end
+
 local function ensureAttachment(vehicle, attachmentId)
     if not vehicle or not attachmentId then return false end
 
@@ -47,6 +69,7 @@ end
 
 local function reconcilePairState(vehicleA, vehicleB, attachmentA, attachmentB)
     if not vehicleA or not vehicleB then return end
+    restoreTrailerScriptIfNeeded(vehicleA)
 
     if TowBarMod.Utils and TowBarMod.Utils.updateAttachmentsForRigidTow then
         TowBarMod.Utils.updateAttachmentsForRigidTow(vehicleA, vehicleB, attachmentA, attachmentB)

42.13/media/lua/client/Landtrain/LandtrainTowbarChainsRebuild.lua

@@ -37,6 +37,28 @@ local function hasAttachment(vehicle, attachmentId)
     return script ~= nil and script:getAttachmentById(attachmentId) ~= nil
 end
 
+local function isTrailerScriptName(scriptName)
+    if not scriptName then return false end
+    return string.find(string.lower(scriptName), "trailer", 1, true) ~= nil
+end
+
+local function shouldForceNotTowingScript(vehicle)
+    if not vehicle then return false end
+    local scriptName = vehicle:getScriptName()
+    return not isTrailerScriptName(scriptName)
+end
+
+local function restoreTrailerScriptIfNeeded(vehicle)
+    if not vehicle then return end
+    if vehicle:getScriptName() ~= "notTowingA_Trailer" then return end
+
+    local md = vehicle:getModData()
+    local originalScript = md and md.towBarOriginalScriptName or nil
+    if originalScript and isTrailerScriptName(originalScript) then
+        vehicle:setScriptName(originalScript)
+    end
+end
+
 local function sideFree(vehicle, attachmentId)
     if vehicle == nil then return false end
     if attachmentId == "trailer" then return vehicle:getVehicleTowing() == nil end
@@ -121,6 +143,27 @@ local function resolvePair(towingVehicle, towedVehicle, preferredA, preferredB)
     return "trailer", "trailerfront"
 end
 
+local function resolveMenuPair(towingVehicle, towedVehicle, preferredA, preferredB)
+    local candidates = {
+        { preferredA, preferredB },
+        { "trailer", "trailerfront" },
+        { towingVehicle and towingVehicle:getTowAttachmentSelf() or nil, towedVehicle and towedVehicle:getTowAttachmentSelf() or nil },
+        { "trailerfront", "trailer" }
+    }
+
+    for _, pair in ipairs(candidates) do
+        local a, b = pair[1], pair[2]
+        if a and b and a ~= b
+            and hasAttachment(towingVehicle, a)
+            and hasAttachment(towedVehicle, b)
+            and canTowByLandtrain(towingVehicle, towedVehicle, a, b, false) then
+            return a, b
+        end
+    end
+
+    return nil, nil
+end
+
 local function clearChangedOffset(vehicle)
     if not vehicle then return end
 end
@@ -534,6 +577,9 @@ local function ensurePairAttached(playerObj, towingVehicle, towedVehicle, prefer
         log("ensurePairAttached skipped: identical vehicles id=" .. tostring(vehicleId(towingVehicle)))
         return false
     end
+
+    restoreTrailerScriptIfNeeded(towingVehicle)
+
     if wouldCreateTowLoop(towingVehicle, towedVehicle) then
         log("ensurePairAttached skipped: loop A=" .. tostring(vehicleId(towingVehicle)) .. " B=" .. tostring(vehicleId(towedVehicle)))
         return false
@@ -670,22 +716,30 @@ local function getLandtrainHookTypeVariants(vehicleA, vehicleB, hasTowBar)
     local variants = {}
     if not hasTowBar or not vehicleA or not vehicleB or vehicleA == vehicleB then return variants end
 
-    if canTowByLandtrain(vehicleA, vehicleB, "trailerfront", "trailer", false) then
+    restoreTrailerScriptIfNeeded(vehicleA)
+    restoreTrailerScriptIfNeeded(vehicleB)
+
+    local function addVariant(towingVehicle, towedVehicle)
+        local attachmentA, attachmentB = resolveMenuPair(towingVehicle, towedVehicle)
+        if not attachmentA or not attachmentB then
+            return false
+        end
+
         table.insert(variants, {
-            name = getText("UI_Text_Towing_attach") .. "\n" .. ISVehicleMenu.getVehicleDisplayName(vehicleB) .. "\n" .. getText("UI_Text_Towing_byTowBar"),
+            name = getText("UI_Text_Towing_attach") .. "\n" .. ISVehicleMenu.getVehicleDisplayName(towedVehicle) .. "\n" .. getText("UI_Text_Towing_byTowBar"),
             func = TowBarMod.Hook.attachByTowBarAction,
-            towingVehicle = vehicleB,
-            towedVehicle = vehicleA,
-            textureName = "tow_bar_icon"
-        })
-    elseif canTowByLandtrain(vehicleA, vehicleB, "trailer", "trailerfront", false) then
-        table.insert(variants, {
-            name = getText("UI_Text_Towing_attach") .. "\n" .. ISVehicleMenu.getVehicleDisplayName(vehicleB) .. "\n" .. getText("UI_Text_Towing_byTowBar"),
-            func = TowBarMod.Hook.attachByTowBarAction,
-            towingVehicle = vehicleA,
-            towedVehicle = vehicleB,
+            towingVehicle = towingVehicle,
+            towedVehicle = towedVehicle,
+            towingPoint = attachmentA,
+            towedPoint = attachmentB,
             textureName = "tow_bar_icon"
         })
+        return true
+    end
+
+    local addedForward = addVariant(vehicleA, vehicleB)
+    if not addedForward then
+        addVariant(vehicleB, vehicleA)
     end
 
     return variants
@@ -1060,8 +1114,7 @@ local function sortPersistedLinks(links, byRearSql)
 end
 
 local function isTowbarPairStateComplete(frontVehicle, rearVehicle)
-    if not isLinkedPair(frontVehicle, rearVehicle) then return false end
-    return rearVehicle:getScriptName() == "notTowingA_Trailer"
+    return isLinkedPair(frontVehicle, rearVehicle)
 end
 
 local function restoreViaAttachWrapper(playerObj, frontVehicle, rearVehicle, attachmentA, attachmentB)
@@ -1129,7 +1182,8 @@ local function restorePersistedLink(playerObj, link, bySql, byHeadOrder)
     end
     if wouldCreateTowLoop(frontVehicle, rearVehicle) then return false end
 
-    if not isLinkedPair(frontVehicle, rearVehicle) then
+    local linkedNow = isLinkedPair(frontVehicle, rearVehicle)
+    if not linkedNow then
         if not canTowByLandtrain(frontVehicle, rearVehicle, link.attachmentA, link.attachmentB, true) then
             return false
         end
@@ -1138,7 +1192,7 @@ local function restorePersistedLink(playerObj, link, bySql, byHeadOrder)
         end
     end
 
-    return ensurePairAttached(playerObj, frontVehicle, rearVehicle, link.attachmentA, link.attachmentB, true)
+    return ensurePairAttached(playerObj, frontVehicle, rearVehicle, link.attachmentA, link.attachmentB, not linkedNow)
 end
 
 local function runPersistedLoadRebuildPass()