fix(ugc): give old cars and rockets a build id when a character loads

Cars and rockets built before builds were recorded have no subkey and no
ugc_modular_build row, so the client has no blueprint id to ask for their
icon with. When a character loads, such an item (a ModularBuildComponent
createdLOT with assemblyPartLOTs but no subkey) gets what a new build
gets: a persistent id as its subkey and a ugc_modular_build row with its
modules and owner. The next save keeps the subkey; nothing is dropped.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

dDatabase/CDClientDatabase/CDClientTables/CDModularBuildComponentTable.cpp

@@ -1,5 +1,7 @@
 #include "CDModularBuildComponentTable.h"
 
+#include <algorithm>
+
 #include <regex>
 #include <string>
 
@@ -55,3 +57,8 @@ std::optional<CDModularBuildComponent> CDModularBuildComponentTable::FindByNumbe
 std::optional<CDModularBuildComponent> CDModularBuildComponentTable::GetByNumberOfParts(const uint32_t numberOfParts) const {
 	return FindByNumberOfParts(GetEntries(), numberOfParts);
 }
+
+bool CDModularBuildComponentTable::IsCreatedLot(LOT lot) const {
+	const auto& entries = GetEntries();
+	return std::any_of(entries.begin(), entries.end(), [lot](const CDModularBuildComponent& build) { return build.createdLOT == lot; });
+}

dDatabase/CDClientDatabase/CDClientTables/CDModularBuildComponentTable.h

@@ -21,6 +21,9 @@ public:
 	// The first build made of this many parts
 	std::optional<CDModularBuildComponent> GetByNumberOfParts(uint32_t numberOfParts) const;
 
+	// Whether a LOT is the item some build becomes (a car or rocket)
+	bool IsCreatedLot(LOT lot) const;
+
 	// Fills numberOfParts and rootPartExampleLOT from a ModularBuildComponent.xml
 	static void ParseXml(std::string_view xml, CDModularBuildComponent& build);
 	static std::optional<CDModularBuildComponent> FindByNumberOfParts(const std::vector<CDModularBuildComponent>& builds, uint32_t numberOfParts);

dGame/dComponents/InventoryComponent.cpp

@@ -19,6 +19,7 @@
 #include "GameMessages.h"
 #include "InventoryMessages.h"
 #include "Database.h"
+#include "CDModularBuildComponentTable.h"
 #include "SkillMessages.h"
 #include "MovementMessages.h"
 #include "SkillComponent.h"
@@ -610,6 +611,27 @@ bool InventoryComponent::HasSpaceForLoot(const Loot::Return& loot) {
 	return true;
 }
 
+namespace {
+	/**
+	 * Cars and rockets built before builds were recorded have no subkey, so the client has no blueprint id to ask for
+	 * their icon with. Give such an item what a new build gets (ModularBuildFinish): a persistent id as its subkey and a
+	 * ugc_modular_build row with its modules. The next save keeps the subkey. Main thread (character load).
+	 */
+	void AssignModularBuildId(Item& item, Entity* owner) {
+		if (item.GetSubKey() != LWOOBJID_EMPTY || !CDClientManager::GetTable<CDModularBuildComponentTable>()->IsCreatedLot(item.GetLot())) return;
+		const auto& config = item.GetConfig();
+		const auto modules = config.find(u"assemblyPartLOTs");
+		if (modules == config.values.end() || !modules->second) return;
+		const auto modulesText = modules->second->GetValueAsString();
+		if (modulesText.empty()) return;
+		const auto id = ObjectIDManager::GetPersistentID();
+		auto* character = owner ? owner->GetCharacter() : nullptr;
+		Database::Get()->InsertUgcBuild(modulesText, id, character ? std::optional(character->GetID()) : std::nullopt);
+		item.SetSubKey(id);
+		LOG("Gave the %i build %llu (made before builds were recorded) the build id %llu", item.GetLot(), item.GetId(), id);
+	}
+}
+
 void InventoryComponent::LoadXml(const tinyxml2::XMLDocument& document) {
 	LoadPetXml(document);
 
@@ -712,6 +734,7 @@ void InventoryComponent::LoadXml(const tinyxml2::XMLDocument& document) {
 			auto* item = new Item(id, lot, inventory, slot, count, bound, {}, parent, subKey);
 
 			item->LoadConfigXml(*itemElement);
+			AssignModularBuildId(*item, m_Parent);
 
 			if (equipped) {
 				const auto info = Inventory::FindItemComponent(lot);