Support location_id in [recall] and [unstore_unit]

(cherry-picked from commit ecc8785)

changelog.md

@@ -50,8 +50,8 @@
  ### WML engine
    * Support formula= key in [variable] ConditionalWML
    * Support to_location in [move_unit], taking a location ID
-   * Support location_id in [teleport] for the target location
    * Suppor dir in [move_unit] to perform relative movements
+   * Support location_id in [teleport], [recall], [unstore_unit] for the target location
    * Support [filter_weapon] in leadership and resistance abilities,
      which activates the ability only when the affected unit is using
      a matching weapon.

data/lua/wml-tags.lua

@@ -831,6 +831,9 @@ wml_actions.unstore_unit = function(cfg)
 	local check_passability = cfg.check_passability ~= false or nil
 	local x = cfg.x or unit.x or -1
 	local y = cfg.y or unit.y or -1
+	if cfg.location_id then
+		x, y = wesnoth.special_locations[cfg.location_id]
+	end
 	wesnoth.add_known_unit(unit.type)
 	if on_board(x, y) then
 		if cfg.find_vacant then

src/game_events/action_wml.cpp

@@ -468,6 +468,7 @@ WML_HANDLER_FUNCTION(recall,, cfg)
 	 */
 	temp_config["x"] = "recall";
 	temp_config["y"] = "recall";
+	temp_config.remove_attribute("location_id");
 	vconfig unit_filter_cfg(temp_config);
 	const vconfig & leader_filter = cfg.child("secondary_unit");
 
@@ -494,7 +495,9 @@ WML_HANDLER_FUNCTION(recall,, cfg)
 				const unit_ptr to_recruit = *u;
 				const unit* pass_check = to_recruit.get();
 				if(!cfg["check_passability"].to_bool(true)) pass_check = nullptr;
-				const map_location cfg_loc = cfg_to_loc(cfg);
+				const map_location cfg_loc = cfg.has_attribute("location_id")
+					? resources::gameboard->map().special_locations().left[cfg["location_id"]]
+					: cfg_to_loc(cfg);
 
 				/// @todo fendrin: comment this monster
 				for (unit_map::const_unit_iterator leader : leaders) {