FULL PRODUCT VERSION :
java version "1.8.0_74"
Java(TM) SE Runtime Environment (build 1.8.0_74-b02)
Java HotSpot(TM) Client VM (build 25.74-b02, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [version 6.1.7601]

A DESCRIPTION OF THE PROBLEM :
When selecting a tabulation that DO NOT belong to tabPane.getTabs(), TabPane selection model keep a pointer on this tab and do not release it.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run that attached application with a memory profiler.

Click on "Select Dummy" button -> 1 sample of MyTab Class in the profiler
Click on "Close Dummy" button -> still 1 sample of MyTab Class in the profiler, even after triggering the GC.

The "Dummy tab" will be released only if a new tab is added in TabPane.

When I look in the code of the select method of TabPane, I understand the result :

@Override public void select(Tab tab) {
            final int itemCount = getItemCount();

            for (int i = 0; i < itemCount; i++) {
                final Tab value = getModelItem(i);
                if (value != null && value.equals(tab)) {
                    select(i);
                    return;
                }
            }
            if (tab != null) {
                setSelectedItem(tab);
            }
        }

If the tab doesn't belng to the TabPane, the setSelectedItem method is called and keep a unnecessary reference on this "tab".



REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package tabpanebug;

import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.Tab;
import javafx.scene.control.TabPane;
import javafx.scene.control.ToolBar;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

/**
 *
 * @author Daniel
 */
public class TabPaneBug extends Application {

    private static class MyTab extends Tab {

        private int i = 0;

        private static int n = 0;
// private Node content;

        public MyTab() {
            setContent(mkContent());
// selectedProperty().addListener((ObservableValue<? extends Boolean> observable, Boolean oldValue, Boolean isSelected) -> {
// if (isSelected) {
// Node content = mkContent();
// setContent(content);
// } else {
// setContent(null);
// }
// });
            setClosable(true);
            setText("Tab" + n++);
        }

        private Node mkContent() {
            VBox vBox = new VBox();
            for (int j = 0; j < 1000; j++) {
                HBox hb = new HBox(new Label("bala" + i), new Label("bala" + i), new Label("boo" + i), new Label("boo" + i));
                vBox.getChildren().add(hb);
            }
            i++;
            return vBox;
        }

    }
    MyTab dummy = new MyTab();

    @Override
    public void start(Stage primaryStage) {
        TabPane tabPane = new TabPane();
// addNTabs(60, tabPane);
        Button add = new Button("add");
        add.setOnAction((ActionEvent event) -> {
            add1Tab(tabPane);
        });

        Button closeAll = new Button("closeAll");
        closeAll.setOnAction((ActionEvent event) -> {
            tabPane.getTabs().clear();
        });
        Button selectDummy = new Button("selectDummy");
        selectDummy.setOnAction((ActionEvent event) -> {
            tabPane.getSelectionModel().select(dummy);
        });
        Button closeDummy = new Button("closeDummy");
        closeDummy.setOnAction((ActionEvent event) -> {
            tabPane.getTabs().remove(dummy);
            dummy = null;
        });


        BorderPane root = new BorderPane();
        root.setTop(new ToolBar(selectDummy, closeDummy, add, closeAll));
        root.setCenter(tabPane);
        Scene scene = new Scene(root, 300, 250);

        primaryStage.setTitle("Tab Pane memory leak!");
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    private void add1Tab(TabPane tabPane) {
        MyTab tab = new MyTab();
        tabPane.getTabs().add(tab);
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        launch(args);
    }

}

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

CUSTOMER SUBMITTED WORKAROUND :
Check if tab belong to tabPane before selecting it