Reject NaN and Inf in check_v3d() too

check_v2f() was already doing this

src/script/common/c_converter.cpp

@@ -199,6 +199,9 @@ v3d check_v3d(lua_State *L, int index)
 	double y = lua_tonumber(L, -2);
 	double z = lua_tonumber(L, -1);
 	lua_pop(L, 3);
+	CHECK_FLOAT(x, "x");
+	CHECK_FLOAT(y, "y");
+	CHECK_FLOAT(z, "z");
 	return v3d(x, y, z);
 }
 

src/unittest/test_scriptapi.cpp

@@ -180,4 +180,17 @@ void TestScriptApi::testVectorReadMix(MyScriptApi *script)
 		EXCEPTION_CHECK(LuaError, check_v3s16(L, -1));
 		lua_pop(L, 1);
 	}
+
+	// same but even the result is undefined
+	const char *errs2[] = {
+		"return {x=0, y=0, z=0/0}", // nan
+		"return {x=0, y=0, z=math.huge}", // inf
+	};
+	for (auto &it : errs2) {
+		infostream << it << std::endl;
+		run(L, it, 1);
+		(void)read_v3s16(L, -1);
+		EXCEPTION_CHECK(LuaError, check_v3s16(L, -1));
+		lua_pop(L, 1);
+	}
 }