Merge branch 'master' into jgrpp

# Conflicts:
#	regression/regression/result.txt
#	src/autoreplace_cmd.cpp
#	src/industry_gui.cpp
#	src/landscape.cpp
#	src/network/network_content.cpp
#	src/newgrf_roadstop.cpp
#	src/pathfinder/yapf/yapf_ship.cpp
#	src/road_gui.cpp
#	src/saveload/ai_sl.cpp
#	src/saveload/saveload.h
#	src/saveload/vehicle_sl.cpp
#	src/station.cpp
#	src/station_gui.cpp
#	src/video/cocoa/cocoa_ogl.h
#	src/video/sdl2_opengl_v.h
#	src/video/video_driver.hpp
#	src/video/win32_v.h
#	src/widget_type.h
#	src/widgets/dropdown.cpp
#	src/widgets/dropdown_type.h
#	src/window.cpp

src/script/api/ai_changelog.hpp

@@ -22,6 +22,7 @@
  * \li AITown::ROAD_LAYOUT_RANDOM
  * \li AIVehicle::IsPrimaryVehicle
  * \li AITileList_StationCoverage
+ * \li AIAirport::GetAirportNumHelipads
  *
  * API removals:
  * \li AIError::ERR_PRECONDITION_TOO_MANY_PARAMETERS, that error is never returned anymore.

src/script/api/game_changelog.hpp

@@ -88,6 +88,7 @@
  * \li GSStoryPage::IsValidStoryPageButtonFlags
  * \li GSStoryPage::IsValidStoryPageButtonCursor
  * \li GSTileList_StationCoverage
+ * \li GSAirport::GetAirportNumHelipads
  *
  * API removals:
  * \li GSError::ERR_PRECONDITION_TOO_MANY_PARAMETERS, that error is never returned anymore.

src/script/api/script_airport.cpp

@@ -173,3 +173,10 @@ extern uint8_t GetAirportNoiseLevelForDistance(const struct AirportSpec *as, uin
 
 	return (int64_t)GetMaintenanceCostFactor(type) * _price[PR_INFRASTRUCTURE_AIRPORT] >> 3;
 }
+
+/* static */ SQInteger ScriptAirport::GetAirportNumHelipads(AirportType type)
+{
+	if (!IsAirportInformationAvailable(type)) return -1;
+
+	return ::AirportSpec::Get(type)->fsm->num_helipads;
+}

src/script/api/script_airport.hpp

@@ -207,6 +207,14 @@ public:
 	 * @return Monthly maintenance cost of the airport type.
 	 */
 	static Money GetMonthlyMaintenanceCost(AirportType type);
+
+	/**
+	 * Get the number of helipads of this airport type.
+	 * @param type The airport type.
+	 * @pre IsAirportInformationAvailable(type)
+	 * @return Number of helipads of this type of airport. When 0 helicopters will go to normal terminals.
+	 */
+	static SQInteger GetAirportNumHelipads(AirportType type);
 };
 
 #endif /* SCRIPT_AIRPORT_HPP */

src/script/api/script_group.cpp

@@ -108,7 +108,10 @@
 /* static */ SQInteger ScriptGroup::GetNumEngines(GroupID group_id, EngineID engine_id)
 {
 	EnforceCompanyModeValid(-1);
-	if (!IsValidGroup(group_id) && group_id != GROUP_DEFAULT && group_id != GROUP_ALL) return -1;
+	if (!ScriptEngine::IsValidEngine(engine_id)) return -1;
+	bool valid_group = IsValidGroup(group_id);
+	if (!valid_group && group_id != GROUP_DEFAULT && group_id != GROUP_ALL) return -1;
+	if (valid_group && ScriptEngine::GetVehicleType(engine_id) != GetVehicleType(group_id)) return -1;
 
 	return GetGroupNumEngines(ScriptObject::GetCompany(), group_id, engine_id);
 }

src/script/api/script_group.hpp

@@ -129,7 +129,9 @@ public:
 	 * Get the number of engines in a given group.
 	 * @param group_id The group to get the number of engines in.
 	 * @param engine_id The engine id to count.
-	 * @pre IsValidGroup(group_id) || group_id == GROUP_ALL || group_id == GROUP_DEFAULT.
+	 * @pre ScriptEngine::IsValidEngine(engine_id).
+	 * @pre (IsValidGroup(group_id) && ScriptEngine::GetVehicleType(engine_id) == GetVehicleType(group_id)) ||
+	     group_id == GROUP_ALL || group_id == GROUP_DEFAULT.
 	 * @game @pre ScriptCompanyMode::IsValid().
 	 * @return The number of engines with id engine_id in the group with id group_id.
 	 */