Every time a keyboard event is received, a render event is emitted when updates are disabled

[friedrich]

When updates are disabled with ups(0) and the window receives a keyboard event, render events are emitted. Here is an example that should render only once a second but instead renders also on every keyboard event:

extern crate piston;
extern crate opengl_graphics;
extern crate graphics;
extern crate glfw_window;

use opengl_graphics::OpenGL;
use piston::window::WindowSettings;
use piston::input::*;
use piston::event_loop::*;
use glfw_window::GlfwWindow as AppWindow;

fn main() {
    let opengl = OpenGL::V3_2;
    let mut window: AppWindow = WindowSettings::new("Test", [100, 100])
        .exit_on_esc(true)
        .opengl(opengl)
        .build()
        .unwrap();

    let mut events = Events::new(EventSettings::new().max_fps(1).ups(0));
    while let Some(e) = events.next(&mut window) {
        if let Some(_) = e.render_args() {
            println!("Render");
        }
    }
}