fix issue where shipyard produces ships with modules without requiring items for the modules if the ship's layout was never changed

src/lib/sim/BuildingSystem.cpp

@@ -419,6 +419,12 @@ void BuildingSystem::setRecipe(BuildingId id, const std::string& recipeId)
     {
         if (site.id == id)
         {
+            // No-op if the recipe is unchanged, so a redundant selection does
+            // not wipe an already-configured ship layout.
+            if (site.recipeId == recipeId)
+            {
+                return;
+            }
             site.recipeId = recipeId;
             site.shipLayout = std::nullopt;
             return;
@@ -430,6 +436,12 @@ void BuildingSystem::setRecipe(BuildingId id, const std::string& recipeId)
     {
         if (building.id == id)
         {
+            // No-op if the recipe is unchanged, so a redundant selection does
+            // not wipe an already-configured ship layout or reset buffers.
+            if (building.recipeId == recipeId)
+            {
+                return;
+            }
             building.recipeId = recipeId;
             building.shipLayout = std::nullopt;
             building.inputBuffer.counts.clear();
@@ -858,7 +870,16 @@ void BuildingSystem::tickShipyardProduction(Tick currentTick)
                 {
                     const Port& p = building.outputPorts[0];
                     const QVector2D spawnPos(p.tile.x() + 0.5f, p.tile.y() + 0.5f);
-                    m_spawnShip(building.recipeId, spawnPos, building.shipLayout);
+                    // A shipyard builds exactly what the player configured and
+                    // paid for. When no layout is set it produces a bare hull, so
+                    // pass an explicit empty layout rather than nullopt: the latter
+                    // would make ShipSystem fall back to the schematic's
+                    // defaultModules (a wave-only loadout) and yield free weapons.
+                    const std::optional<ShipLayoutConfig> layout =
+                        building.shipLayout.has_value()
+                            ? building.shipLayout
+                            : std::make_optional<ShipLayoutConfig>();
+                    m_spawnShip(building.recipeId, spawnPos, layout);
                 }
                 building.production = std::nullopt;
             }

src/test/ShipModuleTest.cpp

@@ -6,6 +6,7 @@
 #include "ConfigLoader.h"
 #include "DynamicBodyComponent.h"
 #include "EntityAdmin.h"
+#include "FactionComponent.h"
 #include "GameConfig.h"
 #include "HealthComponent.h"
 #include "ItemType.h"
@@ -13,6 +14,7 @@
 #include "ModulesConfig.h"
 #include "Rotation.h"
 #include "SensorRangeComponent.h"
+#include "ShipIdentityComponent.h"
 #include "ShipLayout.h"
 #include "ShipStatsCalculator.h"
 #include "ShipSystem.h"
@@ -264,6 +266,50 @@ TEST_CASE("Shipyard: setShipLayout cancels in-progress production",
     CHECK_FALSE(b2->production.has_value());
 }
 
+TEST_CASE("Shipyard: builds a bare hull when no layout is configured",
+          "[modules][shipyard]")
+{
+    Simulation sim(loadConfig(), 42);
+    const ShipDef* def = findSchematic(sim.config(), "interceptor");
+    REQUIRE(def != nullptr);
+    // The schematic carries a weapon in its (wave-only) default loadout. This
+    // test pins that a player shipyard with no configured layout does NOT hand
+    // that weapon out for free: it builds an unarmed bare hull, matching the
+    // base-hull materials it was charged.
+    REQUIRE_FALSE(def->defaultModules.empty());
+
+    const BuildingDef* yardDef = findShipyardDef(sim.config());
+    REQUIRE(yardDef != nullptr);
+
+    const BuildingId yardId = placeShipyard(sim, *yardDef);
+    SimulationTestAccess::buildings(sim).setRecipe(yardId, "interceptor");
+    // Deliberately no setShipLayout: recipe set, layout left unconfigured.
+
+    // Charge only the base-hull materials (an empty layout adds none).
+    fillMaterials(sim, yardId, *def, ShipLayoutConfig{});
+
+    // Tick through one full production cycle so the ship spawns.
+    const Tick cycleTicks = secondsToTicks(def->schematic.productionTimeSeconds);
+    for (Tick i = 0; i <= cycleTicks; ++i)
+    {
+        sim.tick();
+    }
+
+    // Locate the freshly built player ship.
+    entt::entity built = entt::null;
+    sim.admin().forEach<ShipIdentityComponent, FactionComponent>(
+        [&](entt::entity e, const ShipIdentityComponent& si, const FactionComponent& fac)
+        {
+            if (!fac.isEnemy && si.schematicId == "interceptor") { built = e; }
+        });
+    REQUIRE(sim.admin().isValid(built));
+
+    // Bare hull: the schematic's default weapon must NOT have been installed.
+    const bool hasWeapon =
+        findFirstWeaponChild(sim.admin(), built) != entt::null;
+    CHECK_FALSE(hasWeapon);
+}
+
 TEST_CASE("Shipyard: setRecipe clears ship layout", "[modules][shipyard]")
 {
     Simulation sim(loadConfig(), 42);
@@ -292,6 +338,38 @@ TEST_CASE("Shipyard: setRecipe clears ship layout", "[modules][shipyard]")
     CHECK_FALSE(b2->shipLayout.has_value());
 }
 
+TEST_CASE("Shipyard: setRecipe with unchanged recipe keeps ship layout",
+          "[modules][shipyard]")
+{
+    Simulation sim(loadConfig(), 42);
+    const BuildingDef* yardDef = findShipyardDef(sim.config());
+    REQUIRE(yardDef != nullptr);
+
+    const BuildingId yardId = placeShipyard(sim, *yardDef);
+    SimulationTestAccess::buildings(sim).setRecipe(yardId,"interceptor");
+
+    ShipLayoutConfig layout;
+    PlacedModule pm;
+    pm.moduleId = "armor_plate";
+    pm.position = QPoint(0, 0);
+    pm.rotation = Rotation::East;
+    layout.placedModules.push_back(pm);
+    SimulationTestAccess::buildings(sim).setShipLayout(yardId, layout);
+
+    const Building* b1 = sim.buildings().findBuilding(yardId);
+    REQUIRE(b1 != nullptr);
+    REQUIRE(b1->shipLayout.has_value());
+
+    // Re-selecting the same recipe must be a no-op and preserve the layout.
+    SimulationTestAccess::buildings(sim).setRecipe(yardId,"interceptor");
+
+    const Building* b2 = sim.buildings().findBuilding(yardId);
+    REQUIRE(b2 != nullptr);
+    REQUIRE(b2->shipLayout.has_value());
+    REQUIRE(b2->shipLayout->placedModules.size() == 1);
+    CHECK(b2->shipLayout->placedModules[0].moduleId == "armor_plate");
+}
+
 // ---------------------------------------------------------------------------
 // Weapon modifier simulation tests
 // ---------------------------------------------------------------------------