Merge branch 'master' into jgrpp

# Conflicts:
#	.github/workflows/release-linux.yml
#	src/base_consist.h
#	src/blitter/32bpp_optimized.cpp
#	src/blitter/32bpp_optimized.hpp
#	src/blitter/32bpp_sse2.hpp
#	src/blitter/8bpp_optimized.hpp
#	src/gfx_func.h
#	src/industry_cmd.cpp
#	src/industrytype.h
#	src/linkgraph/linkgraphjob.cpp
#	src/mixer.cpp
#	src/newgrf_callbacks.h
#	src/openttd.cpp
#	src/os/macosx/macos.mm
#	src/os/windows/win32.cpp
#	src/pathfinder/npf/npf.cpp
#	src/road_cmd.cpp
#	src/saveload/afterload.cpp
#	src/saveload/saveload.h
#	src/saveload/vehicle_sl.cpp
#	src/sound.cpp
#	src/spritecache.cpp
#	src/spriteloader/spriteloader.hpp
#	src/station_map.h
#	src/timetable_cmd.cpp
#	src/timetable_cmd.h
#	src/timetable_gui.cpp
#	src/town_cmd.cpp
#	src/vehicle_cmd.cpp
#	src/vehicle_gui_base.h
#	src/video/opengl.cpp
#	src/video/opengl.h
#	src/viewport.cpp

src/newgrf_engine.cpp

@@ -1362,6 +1362,20 @@ int GetEngineProperty(EngineID engine, PropertyID property, int orig_value, cons
 	return orig_value;
 }
 
+/**
+ * Test for vehicle build probablity type.
+ * @param v Vehicle whose build probability to test.
+ * @param type Build probability type to test for.
+ * @returns True iff the probability result says so.
+ */
+bool TestVehicleBuildProbability(Vehicle *v, EngineID engine, BuildProbabilityType type)
+{
+	uint16_t p = GetVehicleCallback(CBID_VEHICLE_BUILD_PROBABILITY, std::underlying_type<BuildProbabilityType>::type(type), 0, engine, v);
+	if (p == CALLBACK_FAILED) return false;
+
+	const uint16_t PROBABILITY_RANGE = 100;
+	return p + RandomRange(PROBABILITY_RANGE) >= PROBABILITY_RANGE;
+}
 
 static void DoTriggerVehicle(Vehicle *v, VehicleTrigger trigger, uint16 base_random_bits, bool first)
 {