ADDITIONAL SYSTEM INFORMATION :
This happens on:
Java 1.8 update 131 32bit Linux (redhat 6.8)
Java 1.8 update 172 64bit Windows 10
Java 1.8 update 162 64bit Windows 10


A DESCRIPTION OF THE PROBLEM :
Adding and removing CustomMenuItems from MenuButton and ContextMenu seems to leak memory.
Running JVisualVM and comparing the heap differences shows an ever increasing number of CustomMenuItems, ContextMenuContext$MenuItemContainer objects

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run the test program in this bug report then open JVisualVM.
Take heap dump and wait for 5mins or more before taking another heap dump; then compare the heap dumps, filtering for Javafx.scene.control

Further heap dumps and comparisons will show an ever increasing number of CustomMenuItem and ContextMenuContentXXX objects.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Expected result is number of CustomMenuItem does not increase as all objects added to the menu is removed.
ACTUAL -
Number of CustomMenuItem objects constantly increase.

---------- BEGIN SOURCE ----------
package application;

import java.util.Vector;

import javafx.application.Application;
import javafx.application.Platform;
import javafx.geometry.Side;
import javafx.stage.Stage;
import javafx.scene.Scene;
import javafx.scene.control.MenuButton;
import javafx.scene.layout.HBox;


public class Main extends Application {

public static MenuButton m_Menu = new MenuButton("Menu");

@Override
public void start(Stage primaryStage) {
try {
HBox root = new HBox();
Scene scene = new Scene(root,400,400);
m_Menu.setPopupSide(Side.BOTTOM);
root.getChildren().addAll(m_Menu);
primaryStage.setScene(scene);
primaryStage.show();

//create thread to simulate dynamic adding and
//removing from the menu
Thread t = new Thread(() -> {
dynamicMenuThread();
});
t.start();
} catch(Exception e) {
e.printStackTrace();
}
}

public void dynamicMenuThread() {
Vector<TestMenuItem> list = new Vector<TestMenuItem>();
while(true) {
//create items
Platform.runLater(() -> {
for(int i = 1; i < 6; ++i) { //make menu items
TestMenuItem item = new TestMenuItem(m_Menu.getItems());
item.addToMenu(i);
item.setItem("Item"+i, i);
list.add(item);
}
for(int i = 6; i < 11; ++i) { //make menu items with sub items
TestMenuItem item = new TestMenuItem(m_Menu.getItems());
item.addToMenu(i);
item.setItem("Item"+i, i);
TestMenuItem subItem = item.addSubItem();
subItem.setItem("subItem1", 1);
subItem.addToMenu(0);
list.add(subItem);
subItem = item.addSubItem();
subItem.setItem("subItem2", 2);
subItem.addToMenu(1);
list.add(subItem);
list.add(item);
}
}
);
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
//remove items
while(true) {
if(list.isEmpty()) {
break;
}
Platform.runLater(() -> {
//remove some items
list.remove(0).removeFromMenu();
});
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}

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

--------- END SOURCE ----------

FREQUENCY : always