Fix duplicate mod ids breaking mod selection

Fixes #6780

src/game_initialization/create_engine.cpp

@@ -548,12 +548,12 @@ void create_engine::set_current_era_index(const std::size_t index, bool force)
 	dependency_manager_->try_era_by_index(index, force);
 }
 
-bool create_engine::toggle_mod(int index, bool force)
+bool create_engine::toggle_mod(const std::string& id, bool force)
 {
 	force |= state_.classification().type != campaign_type::type::multiplayer;
 
-	bool is_active = dependency_manager_->is_modification_active(index);
-	dependency_manager_->try_modification_by_index(index, !is_active, force);
+	bool is_active = dependency_manager_->is_modification_active(id);
+	dependency_manager_->try_modification_by_id(id, !is_active, force);
 
 	state_.classification().active_mods = dependency_manager_->get_modifications();
 
@@ -791,7 +791,6 @@ void create_engine::init_extras(const MP_EXTRA extra_type)
 				extras.push_back(std::move(new_extras_metadata));
 			}
 			else {
-				//TODO: use a more visible error message.
 				ERR_CF << "found " << extra_name << " with id=" << extra["id"] << " twice";
 			}
 		}

src/game_initialization/create_engine.hpp

@@ -367,7 +367,7 @@ public:
 	const std::vector<extras_metadata_ptr>& get_const_extras_by_type(const MP_EXTRA extra_type) const;
 	std::vector<extras_metadata_ptr>& get_extras_by_type(const MP_EXTRA extra_type);
 
-	bool toggle_mod(int index, bool force = false);
+	bool toggle_mod(const std::string& id, bool force = false);
 
 	bool generator_assigned() const;
 	bool generator_has_settings() const;

src/game_initialization/depcheck.cpp

@@ -367,9 +367,8 @@ void manager::try_modifications(const std::vector<std::string>& ids, bool force)
 	}
 }
 
-void manager::try_modification_by_index(int index, bool activate, bool force)
+void manager::try_modification_by_id(const std::string& id, bool activate, bool force)
 {
-	std::string id = depinfo_.mandatory_child("modification", index)["id"];
 	std::vector<std::string> mods_copy = mods_;
 
 	if(activate) {

src/game_initialization/depcheck.hpp

@@ -79,11 +79,11 @@ public:
 	/**
 	 * Tries to enable/disable a specific modification
 	 *
-	 * @param index     the index of the modification
+	 * @param id        the id of the modification
 	 * @param activate  activate or deactivate
 	 * @param force     whether to skip dependency check
 	 */
-	void try_modification_by_index(int index, bool activate, bool force = false);
+	void try_modification_by_id(const std::string& id, bool activate, bool force = false);
 
 	/**
 	 * Tries to set the selected era

src/gui/dialogs/campaign_selection.cpp

@@ -384,6 +384,7 @@ void campaign_selection::pre_show(window& window)
 			mod_menu_values.emplace_back("label", mod->name, "checkbox", active);
 
 			mod_states_.push_back(active);
+			mod_ids_.emplace_back(mod->id);
 		}
 
 		mods_menu.set_values(mod_menu_values);
@@ -485,7 +486,7 @@ void campaign_selection::mod_toggled()
 
 	for(unsigned i = 0; i < mod_states_.size(); i++) {
 		if(mod_states_[i]) {
-			engine_.toggle_mod(i);
+			engine_.toggle_mod(mod_ids_[i]);
 		}
 	}
 

src/gui/dialogs/campaign_selection.hpp

@@ -67,6 +67,7 @@ public:
 		, current_difficulty_()
 		, current_sorting_(RANK)
 		, currently_sorted_asc_(true)
+		, mod_ids_()
 	{
 	}
 
@@ -133,6 +134,8 @@ private:
 	std::vector<std::string> last_search_words_;
 
 	inline const static std::string missing_campaign_ = "////missing-campaign////";
+
+	std::vector<std::string> mod_ids_;
 };
 
 } // namespace dialogs

src/gui/dialogs/multiplayer/mp_create_game.cpp

@@ -210,13 +210,12 @@ void mp_create_game::pre_show(window& win)
 
 		toggle_button& mog_toggle = find_widget<toggle_button>(row_grid, "mod_active_state", false);
 
-		const int i = mod_list_->get_item_count() - 1;
 		if(std::find(activemods.begin(), activemods.end(), mod->id) != activemods.end()) {
 			create_engine_.active_mods().push_back(mod->id);
 			mog_toggle.set_value_bool(true);
 		}
 
-		connect_signal_notify_modified(mog_toggle, std::bind(&mp_create_game::on_mod_toggle, this, i, &mog_toggle));
+		connect_signal_notify_modified(mog_toggle, std::bind(&mp_create_game::on_mod_toggle, this, mod->id, &mog_toggle));
 	}
 
 	// No mods, hide the header
@@ -378,7 +377,7 @@ void mp_create_game::pre_show(window& win)
 		create_engine_.set_current_era_index(cfg["index"].to_int()); }, true);
 
 	plugins_context_->set_callback("select_mod",   [this](const config& cfg) {
-		on_mod_toggle(cfg["index"].to_int(), nullptr);
+		on_mod_toggle(cfg["id"].str(), nullptr);
 	}, true);
 
 	plugins_context_->set_accessor("get_selected", [this](const config&) {
@@ -523,14 +522,14 @@ void mp_create_game::on_tab_select()
 	find_widget<stacked_widget>(get_window(), "pager", false).select_layer(i);
 }
 
-void mp_create_game::on_mod_toggle(const int index, toggle_button* sender)
+void mp_create_game::on_mod_toggle(const std::string id, toggle_button* sender)
 {
-	if(sender && (sender->get_value_bool() == create_engine_.dependency_manager().is_modification_active(index))) {
+	if(sender && (sender->get_value_bool() == create_engine_.dependency_manager().is_modification_active(id))) {
 		ERR_MP << "ignoring on_mod_toggle that is already set";
 		return;
 	}
 
-	create_engine_.toggle_mod(index);
+	create_engine_.toggle_mod(id);
 
 	sync_with_depcheck();
 

src/gui/dialogs/multiplayer/mp_create_game.hpp

@@ -101,7 +101,7 @@ private:
 	void on_game_select();
 	void on_tab_select();
 	void on_era_select();
-	void on_mod_toggle(const int index, toggle_button* sender);
+	void on_mod_toggle(const std::string id, toggle_button* sender);
 	void on_random_faction_mode_select();
 
 	std::vector<std::string> get_active_mods();