Fix being able to detach the external factory of the primary unit (#6093

)

lua/defaultcomponents.lua

@@ -1,4 +1,5 @@
 local Buff = import("/lua/sim/buff.lua")
+local Entity = import("/lua/sim/Entity.lua").Entity
 
 ---@class ShieldEffectsComponent : Unit
 ---@field Trash TrashBag
@@ -867,8 +868,21 @@ ExternalFactoryComponent = ClassSimple {
         -- create the factory somewhere completely unrelated
         local px, py, pz = self:GetPositionXYZ(self.FactoryAttachBone)
 
+        -- the anchor entity prevents the "deploy" command from detaching
+        -- the external factory from the base unit
+        local anchorEntity = Entity({Owner = self})
+        self.Trash:Add(anchorEntity)
+        anchorEntity:AttachTo(self, self.FactoryAttachBone)
+
+        -- the anchor unit has the "CARRIER" category, which prevents the
+        -- external factory from being highlighted or selected with the cursor, but
+        -- doesn't prevent selecting it with the exFac button
+        local anchorUnit = CreateUnitHPR('ZXA0003', self.Army, px, py, pz, 0, 0, 0)
+        self.Trash:Add(anchorUnit)
+        anchorUnit:AttachTo(anchorEntity, -1)
+
         self.ExternalFactory = CreateUnitHPR(blueprintIdExternalFactory, self.Army, px, py, pz, 0, 0, 0) --[[@as ExternalFactoryUnit]]
-        self.ExternalFactory:AttachTo(self, self.FactoryAttachBone)
+        self.ExternalFactory:AttachTo(anchorUnit, -1)
         self.ExternalFactory:SetCreator(self)
         self:SetCreator(self.ExternalFactory)
         self.ExternalFactory:SetParent(self)

units/ZXA0003/ZXA0003_script.lua

@@ -0,0 +1,41 @@
+--******************************************************************************************************
+--** Copyright (c) 2022  clyf
+--**
+--** Permission is hereby granted, free of charge, to any person obtaining a copy
+--** of this software and associated documentation files (the "Software"), to deal
+--** in the Software without restriction, including without limitation the rights
+--** to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+--** copies of the Software, and to permit persons to whom the Software is
+--** furnished to do so, subject to the following conditions:
+--**
+--** The above copyright notice and this permission notice shall be included in all
+--** copies or substantial portions of the Software.
+--**
+--** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+--** IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+--** FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+--** AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+--** LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+--** OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+--** SOFTWARE.
+--******************************************************************************************************
+
+local DummyUnit = import('/lua/sim/unit.lua').DummyUnit
+
+---@class ZXA0003 : DummyUnit
+ZXA0003 = ClassUnit(DummyUnit) {
+
+    OnCreate = function (self)
+        self:HideBone(0, true)
+        -- do not allow the unit to be killed or to take damage
+        self.CanTakeDamage = false
+
+        -- do not allow the unit to be reclaimed or targeted by weapons
+        self:SetReclaimable(false)
+        self:SetDoNotTarget(true)
+    end,
+
+    DetachFrom = function(self)
+    end,
+}
+TypeClass = ZXA0003

units/ZXA0003/ZXA0003_unit.bp

@@ -0,0 +1,62 @@
+UnitBlueprint{
+    Categories = {
+        "DUMMYUNIT",
+        "INSIGNIFICANTUNIT",
+        "INVULNERABLE",
+        "UNSELECTABLE",
+        "UNSPAWNABLE",
+        "UNTARGETABLE",
+        "CARRIER",
+    },
+    Defense = {
+        Health = 30,
+        MaxHealth = 30,
+    },
+    Display = {
+        Mesh = {
+            IconFadeInZoom = 2000,
+            LODs = {
+                {
+                    ShaderName = 'Unit',
+                    MeshName = '/Units/UEA0001/UEA0001_lod0.scm',
+                    AlbedoName = '/Units/UEA0001/UEA0001_Albedo.dds',
+                    NormalsName = '/Units/UEA0001/UEA0001_normalsTS.dds',
+                    SpecularName = '/Units/UEA0001/UEA0001_SpecTeam.dds',
+                },
+            },
+        },
+        UniformScale = 0.12,
+    },
+    Economy = {
+        BuildCostEnergy = 0,
+        BuildCostMass = 0,
+        BuildRate = 0.0001,
+        BuildTime = 0,
+        MaxBuildDistance = 100,
+    },
+    Footprint = {
+        MaxSlope = 0.25,
+        SizeX = 1,
+        SizeZ = 1,
+    },
+    General = {
+        CapCost = 0,
+        SelectionPriority = 3,
+    },
+    Intel = { VisionRadius = 0 },
+    Physics = {
+        BankingSlope = 0.5,
+        BuildOnLayerCaps = {
+            LAYER_Air = true,
+            LAYER_Land = false,
+            LAYER_Orbit = false,
+            LAYER_Seabed = false,
+            LAYER_Sub = false,
+            LAYER_Water = false,
+        },
+        MotionType = "RULEUMT_None",
+    },
+    SizeX = 0.01,
+    SizeY = 0.01,
+    SizeZ = 0.01,
+}