[Bug]: UnsupportedOperationException

[Azhrei]

Describe the Bug

Tried to clear all drawings via the Edit > Clear Drawings... menu option and received the exception. None of the drawings were cleared (that I could tell — there were a lot of them).

To Reproduce

1. Create a new campaign
2. Create some drawings on the default Grasslands map
3. Use Edit > Clear Drawings... and watch the fireworks
4. ???
5. Profit!

Expected Behaviour

Drawings are cleared without an exception.

Screenshots

java.lang.UnsupportedOperationException
	at java.base/java.util.Collections$UnmodifiableCollection.clear(Collections.java:1110)
	at net.rptools.maptool.model.Zone.clearDrawables(Zone.java:1499)
	at net.rptools.maptool.client.ClientMessageHandler.lambda$handle$54(ClientMessageHandler.java:971)
	at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:318)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:773)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:720)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:714)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:400)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:87)
	at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
	at net.rptools.maptool.client.swing.MapToolEventQueue.dispatchEvent(MapToolEventQueue.java:54)
	at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:117)
	at java.desktop/java.awt.WaitDispatchSupport$2.run(WaitDispatchSupport.java:191)
	at java.desktop/java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:236)
	at java.desktop/java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:234)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:319)
	at java.desktop/java.awt.WaitDispatchSupport.enter(WaitDispatchSupport.java:234)
	at java.desktop/java.awt.Dialog.show(Dialog.java:1079)
	at java.desktop/java.awt.Component.show(Component.java:1728)
	at java.desktop/java.awt.Component.setVisible(Component.java:1675)
	at java.desktop/java.awt.Window.setVisible(Window.java:1036)
	at java.desktop/java.awt.Dialog.setVisible(Dialog.java:1015)
	at net.rptools.maptool.client.swing.MapToolEventQueue.displayPopup(MapToolEventQueue.java:111)
	at net.rptools.maptool.client.swing.MapToolEventQueue.dispatchEvent(MapToolEventQueue.java:73)
	at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)

MapTool Info

nightly-20231227, built from source on Apple Silicon (M3 Max)

Desktop

macOS Sonoma 14.2.1 (fully updated as of now)

Additional Context

Executed using ./gradlew run. Based on the log.txt, it appears that the server thread displayed the same message with a slightly different code path. The relevant pieces are included below.

(Building the jpackage worked, but I decided I didn't want the package installed as it would've been v0.0.1.)

java.lang.UnsupportedOperationException: null
        at java.base/java.util.Collections$UnmodifiableCollection.clear(Collections.java:1110) ~[?:?]
        at net.rptools.maptool.model.Zone.clearDrawables(Zone.java:1499) ~[main/:?]
        at net.rptools.maptool.server.ServerMessageHandler.lambda$handle$33(ServerMessageHandler.java:654) ~[main/:?]
        at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:318) ~[?:?]
        at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:773) ~[?:?]
        at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:720) ~[?:?]
        at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:714) ~[?:?]
        at java.base/java.security.AccessController.doPrivileged(AccessController.java:400) ~[?:?]
        at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:87) ~[?:?]
        at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742) ~[?:?]
        at net.rptools.maptool.client.swing.MapToolEventQueue.dispatchEvent(MapToolEventQueue.java:54) [main/:?]

[kwvanderlinde]

I think this is my fault. Will look into it.