dispose handlers not called when stop button pressed

Created by: jdf

In the following sketch, the dispose handler is called when the escape key is pressed, but not when the stop button is pressed.

dispose_bug

SampleLibrary s;
void setup() {
  size(200, 200, P3D);
  s = new SampleLibrary(this);
}

void draw() {
  background(255);
  fill(0);
  text("" + millis(), 20, 20);
}

SampleLibrary.java

import processing.core.*;

public class SampleLibrary {

  public SampleLibrary(PApplet parent) {
    parent.registerMethod("dispose", this);
  }

  public void dispose() {
    System.err.println("disposed!");
  }
}

Start by running the provided dispose_bug sketch in Processing and compare pressing Escape with pressing the stop button. Trace the stop-button shutdown path and the registered dispose handler shown in SampleLibrary.java; done means the handler is called for both ways of stopping the sketch.