ADDITIONAL SYSTEM INFORMATION :
Reproducible in Windows 10 and MacOS 10.14.3

A DESCRIPTION OF THE PROBLEM :
In a TextArea it is possible to get an IndexOutOfBoundsException by deleting a word. Enter 2 spaces, delete the 2 spaces and then pressing undo with ctrl-z.

REGRESSION : Last worked in version 8u201

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
* Run supplied test program
* Delete the word "bar"
* Type space
* Type space
* Backspace
* Backspace
* Right-Click and select Undo
Crash!

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Shouldn't crash.
ACTUAL -
Crashes with
Exception in thread "JavaFX Application Thread" java.lang.IndexOutOfBoundsException
at javafx.scene.control.TextArea$TextAreaContent.delete(TextArea.java:219)
at javafx.scene.control.TextInputControl.undo(TextInputControl.java:1100)
at com.sun.javafx.scene.control.behavior.TextInputControlBehavior.callAction(TextInputControlBehavior.java:148)
at com.sun.javafx.scene.control.behavior.TextAreaBehavior.callAction(TextAreaBehavior.java:259)
at com.sun.javafx.scene.control.behavior.BehaviorBase.callActionForEvent(BehaviorBase.java:218)
at com.sun.javafx.scene.control.behavior.TextInputControlBehavior.callActionForEvent(TextInputControlBehavior.java:127)
at com.sun.javafx.scene.control.behavior.BehaviorBase.lambda$new$74(BehaviorBase.java:135)
at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Scene$KeyHandler.process(Scene.java:3964)
at javafx.scene.Scene$KeyHandler.access$1800(Scene.java:3910)
at javafx.scene.Scene.impl_processKeyEvent(Scene.java:2040)
at javafx.scene.Scene$ScenePeerListener.keyEvent(Scene.java:2501)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$KeyEventNotification.run(GlassViewEventHandler.java:197)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$KeyEventNotification.run(GlassViewEventHandler.java:147)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleKeyEvent$354(GlassViewEventHandler.java:228)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleKeyEvent(GlassViewEventHandler.java:227)
at com.sun.glass.ui.View.handleKeyEvent(View.java:546)
at com.sun.glass.ui.View.notifyKey(View.java:966)

---------- BEGIN SOURCE ----------
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.TextArea;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;


// To Reproduce:
// delete the word "bar"
// type space
// type space
// backspace
// backspace
// undo
// crash!
public class TextAreaCrash extends Application
{
    @Override
    public void start(
        Stage primaryStage) throws Exception
    {
        primaryStage.setTitle("TextArea Experiment 1");

        TextArea textArea = new TextArea();
        textArea.setText("foo bar");

        VBox vbox = new VBox(textArea);

        Scene scene = new Scene(vbox, 200, 100);
        primaryStage.setScene(scene);
        primaryStage.show();

    }

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

FREQUENCY : always