Program: 160894
Project: 160894
Buggy source:
@Override public void paintThumb(Graphics g){
  final GraphicsConfig config=GraphicsUtil.setupAAPainting(g);
  Rectangle knobBounds=thumbRect;
  int w=knobBounds.width;
  int h=knobBounds.height;
  g.translate(knobBounds.x,knobBounds.y);
  if (slider.isEnabled()) {
    g.setColor(slider.getBackground());
  }
 else {
    g.setColor(slider.getBackground().darker());
  }
  Boolean paintThumbArrowShape=(Boolean)slider.getClientProperty("String_Node_Str");
  if ((!slider.getPaintTicks() && paintThumbArrowShape == null) || paintThumbArrowShape == Boolean.FALSE) {
    final RoundRectangle2D.Double thumb=new RoundRectangle2D.Double(0,0,w,h,JBUI.scale(6),JBUI.scale(6));
    final RoundRectangle2D.Double innerThumb=new RoundRectangle2D.Double(1,1,w - 2,h - 2,JBUI.scale(6) - 2,JBUI.scale(6) - 2);
    g.setColor(ColorUtil.fromHex("String_Node_Str"));
    ((Graphics2D)g).fill(thumb);
    g.setColor(slider.isEnabled() ? getSelectedTrackColor() : getDisabledTickColor());
    ((Graphics2D)g).fill(innerThumb);
  }
 else   if (slider.getOrientation() == JSlider.HORIZONTAL) {
    int cw=w / 2;
    g.fillRect(1,1,w - 3,h - 1 - cw);
    Polygon p=new Polygon();
    p.addPoint(1,h - cw);
    p.addPoint(cw - 1,h - 1);
    p.addPoint(w - 2,h - 1 - cw);
    g.fillPolygon(p);
    g.setColor(getHighlightColor());
    g.drawLine(0,0,w - 2,0);
    g.drawLine(0,1,0,h - 1 - cw);
    g.drawLine(0,h - cw,cw - 1,h - 1);
    g.setColor(Color.black);
    g.drawLine(w - 1,0,w - 1,h - 2 - cw);
    g.drawLine(w - 1,h - 1 - cw,w - 1 - cw,h - 1);
    g.setColor(getShadowColor());
    g.drawLine(w - 2,1,w - 2,h - 2 - cw);
    g.drawLine(w - 2,h - 1 - cw,w - 1 - cw,h - 2);
  }
 else {
    int cw=h / 2;
    if (slider.getComponentOrientation().isLeftToRight()) {
      g.fillRect(1,1,w - 1 - cw,h - 3);
      Polygon p=new Polygon();
      p.addPoint(w - cw - 1,0);
      p.addPoint(w - 1,cw);
      p.addPoint(w - 1 - cw,h - 2);
      g.fillPolygon(p);
      g.setColor(getHighlightColor());
      g.drawLine(0,0,0,h - 2);
      g.drawLine(1,0,w - 1 - cw,0);
      g.drawLine(w - cw - 1,0,w - 1,cw);
      g.setColor(Color.black);
      g.drawLine(0,h - 1,w - 2 - cw,h - 1);
      g.drawLine(w - 1 - cw,h - 1,w - 1,h - 1 - cw);
      g.setColor(getShadowColor());
      g.drawLine(1,h - 2,w - 2 - cw,h - 2);
      g.drawLine(w - 1 - cw,h - 2,w - 2,h - cw - 1);
    }
 else {
      g.fillRect(5,1,w - 1 - cw,h - 3);
      Polygon p=new Polygon();
      p.addPoint(cw,0);
      p.addPoint(0,cw);
      p.addPoint(cw,h - 2);
      g.fillPolygon(p);
      g.setColor(getHighlightColor());
      g.drawLine(cw - 1,0,w - 2,0);
      g.drawLine(0,cw,cw,0);
      g.setColor(Color.black);
      g.drawLine(0,h - 1 - cw,cw,h - 1);
      g.drawLine(cw,h - 1,w - 1,h - 1);
      g.setColor(getShadowColor());
      g.drawLine(cw,h - 2,w - 2,h - 2);
      g.drawLine(w - 1,1,w - 1,h - 2);
    }
  }
  g.translate(-knobBounds.x,-knobBounds.y);
  config.restore();
}

Fixed version (ground truth):
@Override public void paintThumb(Graphics g){
  final GraphicsConfig config=GraphicsUtil.setupAAPainting(g);
  Rectangle knobBounds=thumbRect;
  int w=knobBounds.width;
  int h=knobBounds.height;
  g.translate(knobBounds.x,knobBounds.y);
  if (slider.isEnabled()) {
    g.setColor(slider.getBackground());
  }
 else {
    g.setColor(slider.getBackground().darker());
  }
  if (isPlainThumb()) {
    double r=slider.getOrientation() == JSlider.HORIZONTAL ? h : w;
    final Ellipse2D.Double thumb=new Ellipse2D.Double(0,0,r,r);
    final Ellipse2D.Double innerThumb=new Ellipse2D.Double(1,1,r - 2,r - 2);
    g.setColor(ColorUtil.fromHex("String_Node_Str"));
    ((Graphics2D)g).fill(thumb);
    g.setColor(slider.isEnabled() ? getSelectedTrackColor() : getDisabledTickColor());
    ((Graphics2D)g).fill(innerThumb);
  }
 else   if (slider.getOrientation() == JSlider.HORIZONTAL) {
    int cw=w / 2;
    g.fillRect(1,1,w - 3,h - 1 - cw);
    Polygon p=new Polygon();
    p.addPoint(1,h - cw);
    p.addPoint(cw - 1,h - 1);
    p.addPoint(w - 2,h - 1 - cw);
    g.fillPolygon(p);
    g.setColor(getHighlightColor());
    g.drawLine(0,0,w - 2,0);
    g.drawLine(0,1,0,h - 1 - cw);
    g.drawLine(0,h - cw,cw - 1,h - 1);
    g.setColor(Color.black);
    g.drawLine(w - 1,0,w - 1,h - 2 - cw);
    g.drawLine(w - 1,h - 1 - cw,w - 1 - cw,h - 1);
    g.setColor(getShadowColor());
    g.drawLine(w - 2,1,w - 2,h - 2 - cw);
    g.drawLine(w - 2,h - 1 - cw,w - 1 - cw,h - 2);
  }
 else {
    int cw=h / 2;
    if (slider.getComponentOrientation().isLeftToRight()) {
      g.fillRect(1,1,w - 1 - cw,h - 3);
      Polygon p=new Polygon();
      p.addPoint(w - cw - 1,0);
      p.addPoint(w - 1,cw);
      p.addPoint(w - 1 - cw,h - 2);
      g.fillPolygon(p);
      g.setColor(getHighlightColor());
      g.drawLine(0,0,0,h - 2);
      g.drawLine(1,0,w - 1 - cw,0);
      g.drawLine(w - cw - 1,0,w - 1,cw);
      g.setColor(Color.black);
      g.drawLine(0,h - 1,w - 2 - cw,h - 1);
      g.drawLine(w - 1 - cw,h - 1,w - 1,h - 1 - cw);
      g.setColor(getShadowColor());
      g.drawLine(1,h - 2,w - 2 - cw,h - 2);
      g.drawLine(w - 1 - cw,h - 2,w - 2,h - cw - 1);
    }
 else {
      g.fillRect(5,1,w - 1 - cw,h - 3);
      Polygon p=new Polygon();
      p.addPoint(cw,0);
      p.addPoint(0,cw);
      p.addPoint(cw,h - 2);
      g.fillPolygon(p);
      g.setColor(getHighlightColor());
      g.drawLine(cw - 1,0,w - 2,0);
      g.drawLine(0,cw,cw,0);
      g.setColor(Color.black);
      g.drawLine(0,h - 1 - cw,cw,h - 1);
      g.drawLine(cw,h - 1,w - 1,h - 1);
      g.setColor(getShadowColor());
      g.drawLine(cw,h - 2,w - 2,h - 2);
      g.drawLine(w - 1,1,w - 1,h - 2);
    }
  }
  g.translate(-knobBounds.x,-knobBounds.y);
  config.restore();
}