Change case of an empty field throws an exception

[mlep]

JabRef version

Latest development branch build (please note build date below)

Operating system

GNU / Linux

Details on version and operating system

JabRef 5.8--2022-10-03--e48ed0c Linux 5.10.0-18-amd64 amd64 Java 18.0.2.1 JavaFX 19+11

Checked with the latest development build

• I made a backup of my libraries before testing the latest development version.
• I have tested the latest development version and the problem persists

Steps to reproduce the behaviour

The issue is similar to #9200
(@TheGor1lla: interested?)

1. Select an entry by double-clicking.
2. Right-click on an empty field from the entry editor.
3. Select Change case > (any of the item).
   An exception is raised.

No exception should be raised.
Menu could be made unavailable for empty strings.

Appendix

...

Log File

Uncaught exception occurred in Thread[JavaFX Application Thread,5,main]
java.lang.NullPointerException: Cannot invoke "String.length()" because "" is null
at org.jabref@5.8.131/org.jabref.logic.formatter.casechanger.TitleParser.determineProtectedChars(Unknown Source)
at org.jabref@5.8.131/org.jabref.logic.formatter.casechanger.TitleParser.parse(Unknown Source)
at org.jabref@5.8.131/org.jabref.logic.formatter.casechanger.Title.(Unknown Source)
at org.jabref@5.8.131/org.jabref.logic.formatter.casechanger.CapitalizeFormatter.format(Unknown Source)
at org.jabref@5.8.131/org.jabref.gui.fieldeditors.contextmenu.DefaultMenu.lambda$getCaseChangeMenu$0(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.EventUtil.fireEventImpl(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.EventUtil.fireEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/javafx.event.Event.fireEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/javafx.scene.control.MenuItem.fire(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.scene.control.ContextMenuContent$MenuItemContainer.lambda$createNodeMenuItemChildren$14(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.EventUtil.fireEventImpl(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.event.EventUtil.fireEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/javafx.event.Event.fireEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/javafx.scene.Scene$ClickGenerator.postProcess(Unknown Source)
at org.jabref.merged.module@5.8.131/javafx.scene.Scene$MouseHandler.process(Unknown Source)
at org.jabref.merged.module@5.8.131/javafx.scene.Scene.processMouseEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/javafx.scene.Scene$ScenePeerListener.mouseEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(Unknown Source)
at java.base/java.security.AccessController.doPrivileged(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$2(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.glass.ui.View.handleMouseEvent(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.glass.ui.View.notifyMouse(Unknown Source)
at org.jabref.merged.module@5.8.131/com.sun.glass.ui.gtk.GtkApplication._runLoop(Native Method)
at org.jabref.merged.module@5.8.131/com.sun.glass.ui.gtk.GtkApplication.lambda$runLoop$11(Unknown Source)
at java.base/java.lang.Thread.run(Unknown Source)

[TheGor1lla]

Handling it the same as the conversion menu sounds good to. I'll propose a change