Add bounds check in script-originated random() and irandom() calls (#2507)

* Add bounds check in script-originated random() and irandom() calls

* Fix bad random/irandom calls in scenarios

* Add explanatory message to (i)random bounds error

Author: GinjaNinja32

scripts/scenario_57_shoreline.lua

@@ -6562,7 +6562,7 @@ function setStations()
 	table.insert(transport_station_list,stationOutpost33)
 	neutralStations = neutralStations + 1
 	psx = random(-60000,-30000)
-	psy = random(612500,70000)
+	psy = random(61250,70000)
 	placeLando()
 	table.insert(place_space,{obj=stationLando,dist=station_dist[stationLando:getTypeName()],shape="circle"})
 	table.insert(stationList,stationLando)
@@ -6684,7 +6684,7 @@ function setStations()
 	art3 = Artifact():setModel("artifact6"):allowPickup(false):setScanningParameters(3,2):setRadarSignatureInfo(random(7,13),random(4,20), random(2,12))
 	art1:setPosition(random(-50000,50000),random(-80000,-70000))
 	art2:setPosition(random(-90000,-75000),random(-40000,-20000))
-	art3:setPosition(random(50000,75000),random(625000,80000))
+	art3:setPosition(random(50000,75000),random(62500,80000))
 	table.insert(place_space,{obj=art1,dist=300,shape="circle"})
 	table.insert(place_space,{obj=art2,dist=300,shape="circle"})
 	table.insert(place_space,{obj=art3,dist=300,shape="circle"})

scripts/scenario_58_race.lua

@@ -947,7 +947,7 @@ function setStations()
 	table.insert(stationList,stationOutpost33)
 	stationOutpost33.comms_data.goods.luxury = {cost = 75, quantity = 5}
 	--Lando
-	stationLando = placeStation(random(-60000,-30000),random(612500,70000),"Lando","Independent","Small Station")
+	stationLando = placeStation(random(-60000,-30000),random(61250,70000),"Lando","Independent","Small Station")
 	table.insert(stationList,stationLando)
 	--Komov
 	stationKomov = placeStation(random(-55000,-30000),random(70000,80000),"Komov","Independent","Small Station")
@@ -1035,7 +1035,7 @@ function setStations()
 	art3 = Artifact():setModel("artifact6"):allowPickup(false):setScanningParameters(3,2):setRadarSignatureInfo(random(7,13),random(4,20), random(2,12))
 	art1:setPosition(random(-50000,50000),random(-80000,-70000))
 	art2:setPosition(random(-90000,-75000),random(-40000,-20000))
-	art3:setPosition(random(50000,75000),random(625000,80000))
+	art3:setPosition(random(50000,75000),random(62500,80000))
 	artChoice = math.random(6)
 	if artChoice == 1 then
 		art1:setDescriptions(_("scienceDescription-artifact", "Unusual object"),_("scienceDescription-artifact", "Artifact with quantum biometric characteristics"))

src/script/scriptRandom.cpp

@@ -52,11 +52,28 @@ static int lua_createRandomGenerator(lua_State* L)
     return 1;
 }
 
+int lua_random(lua_State* L) {
+    auto a = luaL_checknumber(L, -2);
+    auto b = luaL_checknumber(L, -1);
+    if (a > b)
+        return luaL_error(L, "bad call random(%f, %f): lower bound is greater than upper bound", a, b);
+    lua_pushnumber(L, random(a, b));
+    return 1;
+}
+
+int lua_irandom(lua_State* L) {
+    auto a = luaL_checkinteger(L, -2);
+    auto b = luaL_checkinteger(L, -1);
+    if (a > b)
+        return luaL_error(L, "bad call irandom(%d, %d): lower bound is greater than upper bound", a, b);
+    lua_pushinteger(L, irandom(a, b));
+    return 1;
+}
 
 void registerScriptRandomFunctions(sp::script::Environment& env)
 {
-    env.setGlobal("random", static_cast<float(*)(float, float)>(&random));
-    env.setGlobal("irandom", &irandom);
+    env.setGlobal("random", &lua_random);
+    env.setGlobal("irandom", &lua_irandom);
 
     env.setGlobal("RandomGenerator", &lua_createRandomGenerator);
 }