NullPointerException while cloning a TerrainPatch

[stephengold]

While cloning a TerrainPatch to which no Material had yet been applied:

SEVERE: Uncaught exception thrown in Thread[jME3 Main,5,main]
java.lang.NullPointerException
	at com.jme3.terrain.geomipmap.TerrainPatch.cloneFields(TerrainPatch.java:978)
	at com.jme3.util.clone.Cloner.clone(Cloner.java:255)
	at com.jme3.util.clone.Cloner.clone(Cloner.java:160)
	at com.jme3.util.clone.ListCloneFunction.cloneFields(ListCloneFunction.java:66)
	at com.jme3.util.clone.ListCloneFunction.cloneFields(ListCloneFunction.java:43)
	at com.jme3.util.clone.Cloner.clone(Cloner.java:228)
	at com.jme3.util.clone.Cloner.clone(Cloner.java:160)
	at com.jme3.scene.Node.cloneFields(Node.java:729)
	at com.jme3.terrain.geomipmap.TerrainQuad.cloneFields(TerrainQuad.java:1788)
	at com.jme3.util.clone.Cloner.clone(Cloner.java:255)
	at com.jme3.util.clone.Cloner.clone(Cloner.java:160)
	at com.jme3.util.clone.Cloner.deepClone(Cloner.java:139)
	at jme3utilities.Heart.deepCopy(Heart.java:156)

TerrainPatch.cloneFields() is missing a null check:

        this.material = material.clone();

[stephengold]

Thanks, Paul!