Drawing a polygon panics if two consecutive points are equal as of v0.15

[redFrik]

here is a stripped down example that makes nannou 0.15 panic. in 0.14.1 it works ok.
i have noticed the same issue with geom::path::Builder::new() and line_to.

use nannou::prelude::*;
fn main() {
    nannou::sketch(view).size(640, 480).run();
}
fn view(app: &App, frame: Frame) {
    let draw = app.draw();
    frame.clear(BLACK);
    
    let p1 = pt2(100.0, 100.0);
    let p2 = pt2(100.0, 100.0); //if p2 is equal to p1 nannou v0.15 crashes. no to so in v0.14.1
    //let p2 = pt2(100.0, -100.0); //here no problem
    
    let mut points = Vec::new();
    points.push((pt2(0.0, 0.0), rgb(1.0, 1.0, 0.8)));
    points.push((p1, rgb(0.0, 0.0, 0.0)));
    points.push((p2, rgb(0.0, 1.0, 0.0)));
    points.push((pt2(-100.0, -100.0), rgb(1.0, 0.0, 0.0)));
    draw.polygon().points_colored(points);
    draw.to_frame(app, &frame).unwrap();
}

macOS 10.14.6, rustc 1.48.0

thread 'main' panicked at 'assertion failed: `(left != right)`
  left: `0`,
 right: `0`', /Users/Stirling/.cargo/registry/src/github.com-1ecc6299db9ec823/wgpu-0.5.2/src/lib.rs:940:9
stack backtrace:
   0: _rust_begin_unwind
   1: std::panicking::begin_panic_fmt
   2: wgpu::Device::create_buffer_mapped
   3: wgpu::Device::create_buffer_with_data
   4: nannou::draw::renderer::Renderer::encode_render_pass
   5: nannou::draw::renderer::Renderer::render_to_frame
   6: nannou::app::<impl nannou::draw::Draw>::to_frame
   7: line_to::view
   8: nannou::app::run_loop::{{closure}}
   9: <winit::platform_impl::platform::app_state::EventLoopHandler<T> as winit::platform_impl::platform::app_state::EventHandler>::handle_nonuser_event
  10: winit::platform_impl::platform::app_state::Handler::handle_nonuser_event
  11: winit::platform_impl::platform::app_state::AppState::cleared
  12: ____CFXPCCreateCFObjectFromXPCObject_block_invoke
  13: ___CFRunLoopObserverCancel
  14: ___CFRunLoopRun
  15: ___CFTSRToDispatchTime
  16: _RunCurrentEventLoopInMode
  17: _ReceiveNextEventCommon
  18: __BlockUntilNextEventMatchingListInModeWithFilter
  19: __DPSNextEvent
  20: -[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:]
  21: -[NSApplication run]
  22: winit::platform_impl::platform::event_loop::EventLoop<T>::run
  23: winit::event_loop::EventLoop<T>::run
  24: nannou::app::SketchBuilder<E>::run
  25: line_to::main
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.