NPE on copy-paste between two layers where the origin layer has been deleted

[avar]

I:

1. Downloaded data from osm.org
2. Changed the API to api06.dev.osm.org
3. Searched for type:way highway=residential
4. Copied
5. Deleted the layer I copied from
6. Created a new layer
7. Pasted into it

Perhaps the problem is that JOSM doesn't copy the data into memory when the source layer has been deleted?

java.lang.NullPointerException
	at org.openstreetmap.josm.actions.PasteAction.pasteData(PasteAction.java:59)
	at org.openstreetmap.josm.actions.PasteAction.actionPerformed(PasteAction.java:39)
	at javax.swing.SwingUtilities.notifyAction(SwingUtilities.java:1636)
	at javax.swing.JComponent.processKeyBinding(JComponent.java:2851)
	at javax.swing.KeyboardManager.fireBinding(KeyboardManager.java:267)
	at javax.swing.KeyboardManager.fireKeyboardAction(KeyboardManager.java:216)
	at javax.swing.JComponent.processKeyBindingsForAllComponents(JComponent.java:2928)
	at javax.swing.JComponent.processKeyBindings(JComponent.java:2920)
	at javax.swing.JComponent.processKeyEvent(JComponent.java:2814)
	at java.awt.Component.processEvent(Component.java:6040)
	at java.awt.Container.processEvent(Container.java:2041)
	at java.awt.Component.dispatchEventImpl(Component.java:4630)
	at java.awt.Container.dispatchEventImpl(Container.java:2099)
	at java.awt.Component.dispatchEvent(Component.java:4460)
	at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1848)
	at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(DefaultKeyboardFocusManager.java:704)
	at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(DefaultKeyboardFocusManager.java:969)
	at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:841)
	at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:668)
	at java.awt.Component.dispatchEventImpl(Component.java:4502)
	at java.awt.Container.dispatchEventImpl(Container.java:2099)
	at java.awt.Window.dispatchEventImpl(Window.java:2475)
	at java.awt.Component.dispatchEvent(Component.java:4460)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)

[Gubaer]

Can't reproduce with latest.

[avar]

Replying to Gubaer:

Can't reproduce with latest.

It still happens on r2309:

1. Start JOSM
2. Create new layer
3. Draw a 2-node way
4. Copy it
5. Delete the layer
6. Create a new layer
7. Paste into new layer

java.lang.NullPointerException
	at org.openstreetmap.josm.actions.PasteAction.pasteData(PasteAction.java:60)
	at org.openstreetmap.josm.actions.PasteAction.actionPerformed(PasteAction.java:37)
	at javax.swing.SwingUtilities.notifyAction(SwingUtilities.java:1636)
	at javax.swing.JComponent.processKeyBinding(JComponent.java:2851)
	at javax.swing.KeyboardManager.fireBinding(KeyboardManager.java:267)
	at javax.swing.KeyboardManager.fireKeyboardAction(KeyboardManager.java:216)
	at javax.swing.JComponent.processKeyBindingsForAllComponents(JComponent.java:2928)
	at javax.swing.JComponent.processKeyBindings(JComponent.java:2920)
	at javax.swing.JComponent.processKeyEvent(JComponent.java:2814)
	at java.awt.Component.processEvent(Component.java:6040)
	at java.awt.Container.processEvent(Container.java:2041)
	at java.awt.Component.dispatchEventImpl(Component.java:4630)
	at java.awt.Container.dispatchEventImpl(Container.java:2099)
	at java.awt.Component.dispatchEvent(Component.java:4460)
	at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1848)
	at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(DefaultKeyboardFocusManager.java:704)
	at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(DefaultKeyboardFocusManager.java:969)
	at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:841)
	at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:668)
	at java.awt.Component.dispatchEventImpl(Component.java:4502)
	at java.awt.Container.dispatchEventImpl(Container.java:2099)
	at java.awt.Window.dispatchEventImpl(Window.java:2475)
	at java.awt.Component.dispatchEvent(Component.java:4460)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)

[Gubaer]

(In [2312]) fixed #3759: NPE on copy-paste between two layers where the origin layer has been deleted
Only happened if you pasted in a new layer the mouse never entered