ADDITIONAL SYSTEM INFORMATION :
jdk10.0.1, Debian Linux 8 and Windows 7


A DESCRIPTION OF THE PROBLEM :
GridPane does not show nodes properly if rowspan is used.


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Launch compiled code.
Uncomment 01, 02, 03 they'll give another results.


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
GridPane with valid view.

ACTUAL -
GridPane with invalid view.
And one more thing: rows of the first sample have different heights.

---------- BEGIN SOURCE ----------
package testfx;

import javafx.application.Application;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.layout.GridPane;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
import javafx.scene.text.Text;
import javafx.stage.Stage;

public class Main extends Application {
    public static void main(String[] args) {
        launch( args );
    }
    
    private static Node prNode() {
        VBox ret;
        final GridPane gp = new GridPane();
        gp.setGridLinesVisible( true );
        
        /*
        // 01
        gp.add( new Text( "aaa\nbbb\nccc\nddd\neee" ), 0, 0, 1, 2 );
        gp.add( new Text( "aaaa1" ), 1, 0, 1, 1 );
        gp.add( new Text( "aaaa2" ), 1, 1, 1, 1 );
        */
        
        /*
        // 02
        gp.add( new Text( "aaa\nbbb\nccc\nddd\neee" ), 0, 0, 1, 2 );
        gp.add( new Text( "aaaa1" ), 1, 0, 1, 1 );
        gp.add( new Text( "aaaa2" ), 1, 1, 1, 2 ); // '1' -> '2'
        */
        
        // 03
        // if we set rowspan=4 or 2 we'll get another result
        /*gp.add( new Text( "aaa\nbbb\nccc\nddd\neee" ), 0, 0, 1, 3 );
        gp.add( new Text( "aaaa1" ), 1, 0, 1, 1 );
        gp.add( new Text( "aaaa2" ), 1, 1, 1, 2 );
        */
        
        /*
        // 04
        gp.add( new Text( "aaa\nbbb\nccc\nddd\neee" ), 0, 0, 1, 3 );
        gp.add( new Text( "aaaa1" ), 1, 0, 1, 1 );
        gp.add( new Text( "aaaa2" ), 1, 1, 1, 2 );
        gp.add( new Text( "xxx11" ), 2, 0, 1, 1 );
        gp.add( new Text( "xxx21" ), 2, 1, 1, 1 );
        gp.add( new Text( "xxx22" ), 2, 2, 1, 1 );
        */
        
        ret = new VBox( 8, new Text( "text1" ), gp, new Text( "text2" ) );
        
        return ret;
    }
    
    @Override
    public void start(Stage stage) {
        final StackPane root = new StackPane();
        root.getChildren().add( prNode() );
        
        final Scene scene = new Scene( root, 300, 250 );
        
        stage.setTitle( "Hello World!" );
        stage.setScene( scene );
        stage.show();
    }
}

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

FREQUENCY : always