fix user component initialization exception handling & fix fatal error on uninitialized component access

src/logic/scripting/scripting_entities.cpp

@@ -148,7 +148,12 @@ void scripting::on_entity_spawn(
         lua::call(L, 1);
     }
     for (auto& component : components) {
-        create_component(L, -1, *component, args, saved);
+        try {
+            create_component(L, -1, *component, args, saved);
+        } catch (const std::runtime_error& err) {
+            logger.error() << "could not to initialize user component "
+                           << component->name << ": " << err.what();
+        }
     }
 
     for (auto& [packid, pack] : content->getPacks()) {
@@ -166,6 +171,9 @@ static void process_entity_callback(
     const std::string& name,
     std::function<int(lua::State*)> args
 ) {
+    if (env == nullptr) {
+        return;
+    }
     auto L = lua::get_main_state();
     lua::pushenv(L, *env);
     if (lua::hasfield(L, "__disabled")) {

src/objects/Entity.cpp

@@ -71,6 +71,9 @@ dv::value Entity::serialize() const {
     if (!scripts.components.empty()) {
         auto& compsMap = root.object("comps");
         for (auto& comp : scripts.components) {
+            if (comp->env == nullptr) {
+                continue;
+            }
             auto data =
                 scripting::get_component_value(comp->env, SAVED_DATA_VARNAME);
             compsMap[comp->name] = data;