ADDITIONAL SYSTEM INFORMATION :
macOS 10.15.1

openjdk version "13.0.1" 2019-10-15
OpenJDK Runtime Environment (build 13.0.1+9)
OpenJDK 64-Bit Server VM (build 13.0.1+9, mixed mode, sharing)

JavaFX 13.0.1


A DESCRIPTION OF THE PROBLEM :
When putting more than one file into the ClipboardContent via drag and drop the virtual machine crashes. *Exactly* one file works perfectly, more than one file leads to the creash. The functionality worked fine on Java 11 but produces the crash with Java 13.

REGRESSION : Last worked in version 11.0.5

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Execute the main method of the attached source code

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The files should be correctly copied to the OS
ACTUAL -
The system crashes

---

2019-11-10 00:14:54.299 java[50285:1157021] *** Terminating app due to uncaught exception 'NSGenericException', reason: 'There are 2 items on the pasteboard, but 1 drag images. There must be 1 draggingItem per pasteboardItem.'
*** First throw call stack:
(
0 CoreFoundation 0x00007fff2db3af53 __exceptionPreprocess + 250
1 libobjc.A.dylib 0x00007fff63c00835 objc_exception_throw + 48
2 CoreFoundation 0x00007fff2db3ada9 +[NSException raise:format:] + 189
3 AppKit 0x00007fff2afc93bb -[NSDraggingSession(NSInternal) _initWithPasteboard:image:offset:source:] + 247
4 AppKit 0x00007fff2afc8dee -[NSCoreDragManager dragImage:fromWindow:at:offset:event:pasteboard:source:slideBack:] + 1889
5 AppKit 0x00007fff2afc867d -[NSWindow(NSDrag) dragImage:at:offset:event:pasteboard:source:slideBack:] + 134
6 libglass.dylib 0x0000000132f9f618 -[GlassViewDelegate startDrag:] + 1080
7 libglass.dylib 0x0000000132faa0c7 Java_com_sun_glass_ui_mac_MacPasteboard__1putItemsFromArray + 2439
8 ??? 0x000000011c1d8c90 0x0 + 4766665872
9 ??? 0x000000011c1d2a90 0x0 + 4766640784
10 ??? 0x000000011c1d2a90 0x0 + 4766640784
11 ??? 0x000000011c1d2a90 0x0 + 4766640784
)
libc++abi.dylib: terminating with uncaught exception of type NSException

---------- BEGIN SOURCE ----------
package test;

import java.io.File;
import java.util.List;

import javafx.application.Application;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.input.ClipboardContent;
import javafx.scene.input.Dragboard;
import javafx.scene.input.TransferMode;
import javafx.stage.Stage;

public class Test {

    public static void main(String[] args) {
        Application.launch(TestApplication.class, args);
    }

    public static class TestApplication extends Application {

        @Override
        public void start(Stage primaryStage) throws Exception {

            Label label = new Label("HELLO!");
            label.setOnDragDetected(event -> {
// List<File> files1 = List.of(new File("/bin/bash"));
                List<File> files2 = List.of(new File("/bin/bash"), new File("/bin/cat"));
                Dragboard dragBoard = ((Node)event.getSource()).startDragAndDrop(TransferMode.COPY);
                ClipboardContent clipboardContent = new ClipboardContent();
                clipboardContent.putFiles(files2);
                dragBoard.setContent(clipboardContent);
                event.consume();
            });

            primaryStage.setScene(new Scene(label));
            primaryStage.show();


        }

    }

}

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

CUSTOMER SUBMITTED WORKAROUND :
Downgrading to a lower Java version. Functionality works fine with Java 11.

FREQUENCY : always