Game Events/Manager: skip disabled assertion if write_events is called mid-event

This reverts afaa75842c and replaces it with a more general
no-assert-during-events check. This is because there are other instances besides [inspect]
where this function can be called mid-event, and it wouldn't be convenient to add nested
'strict' parameters to multiple functions just to handle them.

Fixes #2750.

changelog.md

@@ -71,6 +71,7 @@
    * Fixed images with no alpha channel rendering incorrectly.
    * Fixed unit selection not persisting between uses of Create Unit.
    * Fixed assertion when undoing actions in a synced context.
+   * Fixed assertion when saving game events mid-event.
 
 ## Version 1.13.12
  ### Security fixes

src/game_events/manager.cpp

@@ -132,16 +132,26 @@ void manager::add_events(const config::const_child_itors& cfgs, const std::strin
 	}
 }
 
-void manager::write_events(config& cfg, bool strict) const
+void manager::write_events(config& cfg) const
 {
 	for(const handler_ptr& eh : event_handlers_->get_active()) {
-		if(eh && !eh->is_menu_item()) {
-			if(strict) {
-				assert(!eh->disabled());
-			}
-
-			cfg.add_child("event", eh->get_config());;
+		if(!eh || eh->is_menu_item()) {
+			continue;
 		}
+
+		// This function may be invoked mid-event, such as via [inspect] (the inspector writes
+		// the events to a local config) or if an out-of-sync error happens in MP. In that case,
+		// it's possible for the currently running event is already disabled. That would happen
+		// if it's a first-time-only event; those are disabled before their actions are run. In
+		// that case, skip disabled events. If invoked from outside an event, however, there
+		// should be no disabled events in the list, so assert if one is found.
+		if(eh->disabled() && is_event_running()) {
+			continue;
+		} else {
+			assert(!eh->disabled());
+		}
+
+		cfg.add_child("event", eh->get_config());;
 	}
 
 	cfg["unit_wml_ids"] = utils::join(unit_wml_ids_);

src/game_events/manager.hpp

@@ -68,7 +68,7 @@ public:
 
 	void add_events(const config::const_child_itors& cfgs, const std::string& type = std::string());
 
-	void write_events(config& cfg, bool strict = true) const;
+	void write_events(config& cfg) const;
 
 	using event_func_t = std::function<void(game_events::manager&, handler_ptr&)>;
 	void execute_on_events(const std::string& event_id, event_func_t func);

src/gui/dialogs/gamestate_inspector.cpp

@@ -509,7 +509,7 @@ const display_context& single_mode_controller::dc() const {
 event_mode_controller::event_mode_controller(gamestate_inspector::controller& c)
 	: single_mode_controller(c)
 {
-	single_mode_controller::events().write_events(events, false);
+	single_mode_controller::events().write_events(events);
 }
 
 void variable_mode_controller::show_list(tree_view_node& node)