FULL PRODUCT VERSION :
java version "1.8.0_66"
Java(TM) SE Runtime Environment (build 1.8.0_66-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.66-b17, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
OS X 10.11.1
Windows 7

A DESCRIPTION OF THE PROBLEM :
The documentation for GraphicsContext.clearRect states that it uses the current clip. This works as expected if the clip is set to a rectangle. However, if set to a non-rectangular shape using eg GraphicsContext.arc or lineTo to draw any other shape, clearRect has no effect at all.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Compile and run the attached program.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
A blank window is shown.
ACTUAL -
A window with a circle drawn in it is shown.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.canvas.Canvas;
import javafx.scene.canvas.GraphicsContext;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;

public class Main extends Application {
    @Override
    public void start(Stage primaryStage) {
        try {
            BorderPane root = new BorderPane();
            Scene scene = new Scene(root, 400, 400);
            primaryStage.setScene(scene);
            primaryStage.show();

            Canvas canvas = new Canvas(400, 400);
            root.getChildren().add(canvas);

            GraphicsContext context = canvas.getGraphicsContext2D();
            context.beginPath();
            context.arc(50, 50, 40, 40, 0, 360);
            context.closePath();
            context.clip();
            context.fillRect(0, 0, 200, 200); //Draws a circle, illustrates clip is set correctly
            context.clearRect(0, 0, 200, 200); //Has no effect
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        launch(args);
    }
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
GraphicsContext.fillRect works as expect using the clip mask. So it is possible to erase in non-rectangular shapes by drawing with the background colour using fillRect. However, fillRect does not working for setting a transparent background so this workaround is not entirely effective.