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 :
Microsoft Windows [Version 6.1.7601]

A DESCRIPTION OF THE PROBLEM :
If a TreeView/TreeTableView has a vertical scroll bar and I scroll to the end of the tree and then resize my window to be larger than the tree, I get the following warnings:

For TreeView:
Oct 23, 2015 5:42:34 PM com.sun.javafx.scene.control.skin.VirtualFlow addTrailingCells
INFO: index exceeds maxCellCount. Check size calculations for class com.sun.javafx.scene.control.skin.TreeViewSkin$1

For TreeTableView:
Oct 23, 2015 5:42:59 PM com.sun.javafx.scene.control.skin.VirtualFlow addTrailingCells
INFO: index exceeds maxCellCount. Check size calculations for class javafx.scene.control.TreeTableRow

Intermittently, one or two of the associated TreeItem icons will be missing as well.


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
package sample;

import javafx.application.Application;
import javafx.beans.property.ReadOnlyStringWrapper;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class Main extends Application {

    @Override
    public void start(Stage primaryStage) throws Exception {
        Button treeViewButton = new Button("TreeView Test Case");
        treeViewButton.setOnAction(e -> openTreeViewTestCase());

        Button treeTableViewButton = new Button("TreeTableView Test Case");
        treeTableViewButton.setOnAction(e -> openTreeTableViewTestCase());

        VBox root = new VBox(10, treeViewButton, treeTableViewButton);
        primaryStage.setScene(new Scene(root));
        primaryStage.show();
    }

    private void openTreeViewTestCase() {
        TreeView<String> tree = new TreeView<>();

        TreeItem<String> treeRoot = new TreeItem<>("root");
        treeRoot.setExpanded(true);
        tree.setRoot(treeRoot);

        for (int i = 0; i < 10; i++)
            treeRoot.getChildren().add(new TreeItem<>("child"));

        StackPane root = new StackPane();
        root.getChildren().add(tree);

        Stage stage = new Stage();
        stage.setTitle("Scroll to end and resize window to show full tree");
        stage.setScene(new Scene(root, 500, 200));
        stage.show();
    }

    private void openTreeTableViewTestCase() {
        TreeTableView<String> treeTable = new TreeTableView<>();
        TreeTableColumn<String, String> col = new TreeTableColumn<>("Scroll to end and resize window to show full tree");
        col.setPrefWidth(330);
        col.setCellValueFactory(param -> new ReadOnlyStringWrapper(param.getValue().getValue()));
        treeTable.getColumns().add(col);

        TreeItem<String> treeRoot = new TreeItem<>("root");
        treeRoot.setExpanded(true);
        treeTable.setRoot(treeRoot);

        for (int i = 0; i < 10; i++)
            treeRoot.getChildren().add(new TreeItem<>("child"));

        StackPane root = new StackPane();
        root.getChildren().add(treeTable);

        Stage stage = new Stage();
        stage.setTitle("Scroll to end and resize window to show full tree");
        stage.setScene(new Scene(root, 500, 200));
        stage.show();
    }

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

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