fix OOS when undoing after deactivating DSU

previously the 'auto_shroud' replay action also casued the shroud to be
updated (resources::undo_stack->commit_vision()), this caused bugs
becasue it added 2 entries on the undo stack, which caused 2 actionas to
be removed from the replay when undoing after deacticvating delayed
shroud updates.

Also there was no need to do resources::undo_stack->commit_vision(); on
'auto_shroud' replay command becasue we usually automaticly put a
'update_shroud'  command before every 'auto_shroud' command.

src/menu_events.cpp

@@ -791,8 +791,6 @@ void menu_handler::toggle_shroud_updates(int side_num)
 	team &current_team = teams()[side_num - 1];
 	bool auto_shroud = current_team.auto_shroud_updates();
 	// If we're turning automatic shroud updates on, then commit all moves
-	// TODO: currently synced_context::run_in_synced_context("auto_shroud", replay_helper::get_auto_shroud(!auto_shroud));
-	// Also calls update_shroud_now so eigher remove this one or that one.
 	if (!auto_shroud) update_shroud_now(side_num);
 
 	// Toggle the setting and record this.

src/synced_commands.cpp

@@ -342,9 +342,9 @@ SYNCED_COMMAND_HANDLER_FUNCTION(auto_shroud, child,  use_undo, /*show*/, /*error
 	team &current_team = (*resources::teams)[current_team_num - 1];
 
 	bool active = child["active"].to_bool();
-	// Turning on automatic shroud causes vision to be updated.
-	if ( active )
-		resources::undo_stack->commit_vision();
+	// We cannot update shroud here like 'if(active) resources::undo_stack->commit_vision();'.
+	// Becasue the undo.cpp code assumes exactly 1 entry in the undo stack per entry in the replay.
+	// And doing so would create a second entry in the undo stack for this 'auto_shroud' entry.
 	current_team.set_auto_shroud_updates(active);
 	resources::undo_stack->add_auto_shroud(active);
 	return true;