fix bug where selecting the same layout for a shipyard discarded the current progress and buffers

src/test/BuildingConfigTest.cpp

@@ -103,14 +103,25 @@ TEST_CASE("readBuildingConfig returns a shipyard's schematic and layout",
 
     const BuildingId id = placeOperational(sim, cfg, BuildingType::Shipyard, QPoint(0, 0));
     SimulationTestAccess::buildings(sim).setRecipe(SimulationTestAccess::state(sim), id, schematic->id);
-    SimulationTestAccess::buildings(sim).setShipLayout(SimulationTestAccess::state(sim), id, ShipLayoutConfig{});
+
+    // A real layout, not an empty one: applying an empty layout to a shipyard that has
+    // none is a no-op (REQ-MAT-INPUT-BUFFER), so it would leave nothing to read back.
+    ShipLayoutConfig layout;
+    PlacedModule placed;
+    placed.moduleId = "armor_plate";
+    placed.position = QPoint(0, 0);
+    placed.rotation = Rotation::East;
+    layout.placedModules.push_back(placed);
+    SimulationTestAccess::buildings(sim).setShipLayout(SimulationTestAccess::state(sim), id, layout);
 
     const std::optional<BuildingConfig> config = readBuildingConfig(sim, id);
     REQUIRE(config.has_value());
     CHECK(config->type == BuildingType::Shipyard);
     REQUIRE(config->recipeId.has_value());
     CHECK(*config->recipeId == schematic->id);
-    CHECK(config->shipLayout.has_value());
+    REQUIRE(config->shipLayout.has_value());
+    REQUIRE(config->shipLayout->placedModules.size() == 1);
+    CHECK(config->shipLayout->placedModules[0].moduleId == "armor_plate");
 }
 
 TEST_CASE("readBuildingConfig reads a queued construction site", "[blueprint]")

src/test/ShipModuleTest.cpp

@@ -262,6 +262,123 @@ TEST_CASE("Shipyard: setShipLayout cancels in-progress production",
     CHECK_FALSE(b2->production.has_value());
 }
 
+// Applying a configuration a building already has is a no-op (REQ-MAT-INPUT-BUFFER).
+// setRecipe has always worked this way; setShipLayout did not, and wiped the shipyard
+// on every re-apply. That matters now that a blueprint configuration transfer
+// (REQ-UI-BLUEPRINT-TRANSFER) can be clicked repeatedly onto matching shipyards.
+
+TEST_CASE("Shipyard: re-applying the same layout keeps production and buffers",
+          "[modules][shipyard]")
+{
+    Simulation sim(loadTestConfig(), 42);
+    const ShipDef* def = findSchematic(sim.getConfig(), "interceptor");
+    REQUIRE(def != nullptr);
+    const BuildingDef* yardDef = findShipyardDef(sim.getConfig());
+    REQUIRE(yardDef != nullptr);
+
+    const BuildingId yardId = placeShipyard(sim, *yardDef);
+    SimulationTestAccess::buildings(sim).setRecipe(SimulationTestAccess::state(sim), 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(SimulationTestAccess::state(sim), yardId, layout);
+    fillMaterials(sim, yardId, *def, layout);
+    sim.tick();
+
+    const Building* before = findBuilding(sim.getFactoryState(), yardId);
+    REQUIRE(before != nullptr);
+    REQUIRE(before->production.has_value());
+    const Tick completesAt = before->production->completesAt;
+
+    // A separately built but equal layout: equality is by value, not by identity.
+    ShipLayoutConfig sameLayout;
+    sameLayout.placedModules.push_back(pm);
+    SimulationTestAccess::buildings(sim).setShipLayout(SimulationTestAccess::state(sim), yardId, sameLayout);
+
+    const Building* after = findBuilding(sim.getFactoryState(), yardId);
+    REQUIRE(after != nullptr);
+    REQUIRE(after->production.has_value());
+    CHECK(after->production->completesAt == completesAt);
+    CHECK(after->inputBuffer.caps.at(ItemType{"iron_ingot"}) == 10);
+}
+
+TEST_CASE("Shipyard: an empty layout on an unconfigured shipyard changes nothing",
+          "[modules][shipyard]")
+{
+    // An unset layout and an empty one are the same state everywhere that matters, so
+    // clearing an already-unconfigured shipyard must not cancel its cycle. This is the
+    // case a transfer from a layout-less source shipyard produces.
+    Simulation sim(loadTestConfig(), 42);
+    const ShipDef* def = findSchematic(sim.getConfig(), "interceptor");
+    REQUIRE(def != nullptr);
+    const BuildingDef* yardDef = findShipyardDef(sim.getConfig());
+    REQUIRE(yardDef != nullptr);
+
+    const BuildingId yardId = placeShipyard(sim, *yardDef);
+    SimulationTestAccess::buildings(sim).setRecipe(SimulationTestAccess::state(sim), yardId, "interceptor");
+
+    ShipLayoutConfig emptyLayout;
+    fillMaterials(sim, yardId, *def, emptyLayout);
+    sim.tick();
+
+    const Building* before = findBuilding(sim.getFactoryState(), yardId);
+    REQUIRE(before != nullptr);
+    REQUIRE(before->production.has_value());
+    REQUIRE_FALSE(before->shipLayout.has_value());
+
+    SimulationTestAccess::buildings(sim).setShipLayout(SimulationTestAccess::state(sim), yardId, emptyLayout);
+
+    const Building* after = findBuilding(sim.getFactoryState(), yardId);
+    REQUIRE(after != nullptr);
+    CHECK(after->production.has_value());
+    CHECK_FALSE(after->shipLayout.has_value());
+}
+
+TEST_CASE("Shipyard: the same modules in a different order count as a change",
+          "[modules][shipyard]")
+{
+    // Layout equality is deliberately order-sensitive (see ShipLayout.h): the safe
+    // answer when in doubt is "changed", which costs a buffer reset rather than
+    // leaving a shipyard building the wrong ship.
+    Simulation sim(loadTestConfig(), 42);
+    const ShipDef* def = findSchematic(sim.getConfig(), "interceptor");
+    REQUIRE(def != nullptr);
+    const BuildingDef* yardDef = findShipyardDef(sim.getConfig());
+    REQUIRE(yardDef != nullptr);
+
+    const BuildingId yardId = placeShipyard(sim, *yardDef);
+    SimulationTestAccess::buildings(sim).setRecipe(SimulationTestAccess::state(sim), yardId, "interceptor");
+
+    PlacedModule armor;
+    armor.moduleId = "armor_plate";
+    armor.position = QPoint(0, 0);
+    armor.rotation = Rotation::East;
+    PlacedModule sensor;
+    sensor.moduleId = "sensor_booster";
+    sensor.position = QPoint(1, 0);
+    sensor.rotation = Rotation::East;
+
+    ShipLayoutConfig layout;
+    layout.placedModules.push_back(armor);
+    layout.placedModules.push_back(sensor);
+    SimulationTestAccess::buildings(sim).setShipLayout(SimulationTestAccess::state(sim), yardId, layout);
+    fillMaterials(sim, yardId, *def, layout);
+    sim.tick();
+    REQUIRE(findBuilding(sim.getFactoryState(), yardId)->production.has_value());
+
+    ShipLayoutConfig reordered;
+    reordered.placedModules.push_back(sensor);
+    reordered.placedModules.push_back(armor);
+    SimulationTestAccess::buildings(sim).setShipLayout(SimulationTestAccess::state(sim), yardId, reordered);
+
+    CHECK_FALSE(findBuilding(sim.getFactoryState(), yardId)->production.has_value());
+}
+
 TEST_CASE("Shipyard: builds a bare hull when no layout is configured",
           "[modules][shipyard]")
 {