Merge pull request #147 from maarzt/fix-no-features-installed

Tiny fix, NullPointerException in FeatureComputationPanel/Model

src/main/java/org/mastodon/feature/ui/FeatureComputationModel.java

@@ -115,7 +115,7 @@ public void setVisible( final FeatureSpec< ?, ? > spec, final boolean visible )
 	public Collection< FeatureSpec< ?, ? > > getFeatureSpecs( final Class< ? > target )
 	{
 		final Collection< FeatureSpec< ?, ? > > fs = featureSpecsTargetMap.get( target );
-		return null == fs ? null : Collections.unmodifiableCollection( fs );
+		return null == fs ? Collections.emptyList() : Collections.unmodifiableCollection( fs );
 	}
 
 	public FeatureSpec< ?, ? > getFeatureSpec( final String featureKey )