Fix unbuilt units staying around when issued with BuildMobile to external factories and cancelled

changelog/snippets/fix.6702.md

@@ -0,0 +1 @@
+- (#6702) Fix being able to store unbuilt units inside carriers and place unbuilt units on the ground with the fatboy.

lua/defaultcomponents.lua

@@ -940,18 +940,22 @@ ExternalFactoryComponent = ClassSimple {
     ---@param self Unit | ExternalFactoryComponent
     ---@param unitBeingBuilt Unit
     OnStopBuildWithStorage = function(self, unitBeingBuilt)
-        --local unitBeingBuilt = self.UnitBeingBuilt
-        unitBeingBuilt:DetachFrom(true)
-        self:DetachAll(self.BuildAttachBone)
-
-        if not self:TransportHasAvailableStorage() or self:GetStat('AutoDeploy', 0).Value == 1 then
-            unitBeingBuilt:ShowBone(0, true)
+        -- Unbuilt units can be in `OnStopBuild` when a `BuildMobile` order gets cancelled. They shouldn't be put into storage.
+        if unitBeingBuilt:GetFractionComplete() < 1 then
+            unitBeingBuilt:Destroy()
         else
-            self:AddUnitToStorage(unitBeingBuilt)
-            ForkThread(self.ClearOrdersThread, self, unitBeingBuilt)
-        end
+            unitBeingBuilt:DetachFrom(true)
+            self:DetachAll(self.BuildAttachBone)
+
+            if not self:TransportHasAvailableStorage() or self:GetStat('AutoDeploy', 0).Value == 1 then
+                unitBeingBuilt:ShowBone(0, true)
+            else
+                self:AddUnitToStorage(unitBeingBuilt)
+                ForkThread(self.ClearOrdersThread, self, unitBeingBuilt)
+            end
 
-        self:RequestRefreshUI()
+            self:RequestRefreshUI()
+        end
         ChangeState(self, self.IdleState)
     end,
 

units/UEL0401/UEL0401_script.lua

@@ -102,6 +102,10 @@ UEL0401 = ClassUnit(TMobileFactoryUnit, ExternalFactoryComponent) {
     ---@param unitBeingBuilt Unit
     OnStopBuild = function(self, unitBeingBuilt)
         TMobileFactoryUnit.OnStopBuild(self, unitBeingBuilt)
+        -- Unbuilt units can be in `OnStopBuild` when a `BuildMobile` order gets cancelled.
+        if unitBeingBuilt:GetFractionComplete() < 1 then
+            unitBeingBuilt:Destroy()
+        end
         self.BuildingUnit = false
     end,
 
@@ -186,6 +190,13 @@ UEL0401 = ClassUnit(TMobileFactoryUnit, ExternalFactoryComponent) {
         ---@param unitBeingBuilt Unit
         OnStopBuild = function(self, unitBeingBuilt)
             TMobileFactoryUnit.OnStopBuild(self, unitBeingBuilt)
+            -- Unbuilt units can be in `OnStopBuild` when a `BuildMobile` order gets cancelled.
+            if unitBeingBuilt:GetFractionComplete() < 1 then
+                unitBeingBuilt:Destroy()
+                ChangeState(self, self.IdleState)
+                return
+            end
+
             ChangeState(self, self.RollingOffState)
         end,
     },