1 files changed, 21 insertions, 1 deletions

diff --git a/src/cuchaz/enigma/mapping/Ancestries.java b/src/cuchaz/enigma/mapping/Ancestries.java
index b7a5e24..f77a00e 100644
--- a/src/cuchaz/enigma/mapping/Ancestries.java
+++ b/src/cuchaz/enigma/mapping/Ancestries.java
@@ -26,6 +26,7 @@ import javassist.CtClass;
 import javassist.NotFoundException;
 import javassist.bytecode.Descriptor;
 
+import com.beust.jcommander.internal.Lists;
 import com.google.common.collect.Maps;
 
 import cuchaz.enigma.Constants;
@@ -121,11 +122,30 @@ public class Ancestries implements Serializable
                 while( className != null )
                 {
                         className = getSuperclassName( className );
-                        ancestors.add( className );
+                        if( className != null )
+                        {
+                                ancestors.add( className );
+                        }
                 }
                 return ancestors;
         }
         
+        public List<String> getSubclasses( String className )
+        {
+                // linear search is fast enough for now
+                List<String> subclasses = Lists.newArrayList();
+                for( Map.Entry<String,String> entry : m_superclasses.entrySet() )
+                {
+                        String subclass = entry.getKey();
+                        String superclass = entry.getValue();
+                        if( className.equals( superclass ) )
+                        {
+                                subclasses.add( subclass );
+                        }
+                }
+                return subclasses;
+        }
+        
         private boolean isJre( String className )
         {
                 return className.startsWith( "java/" )