detect volume and tone pots

diylc/diylc-core/src/org/diylc/netlist/Tree.java

@@ -247,6 +247,9 @@ public class Tree {
     if (p1 == null || p2 == null)
       return null;
     
+    if (p1 == p2)
+      return p1;
+    
     if (p1 != p2)
       return this;
     
@@ -272,6 +275,20 @@ public class Tree {
     return findCommonParent(t.get(0), findCommonParent(remainder));
   }
   
+  public Tree findParent(Tree t) {
+    if (children == null)
+      return null;
+    if (children.contains(t))
+      return this;
+    for (Tree c : children)
+    {
+      Tree p = c.findParent(t);
+      if (p != null)
+        return p;
+    }
+    return null;
+  }
+  
   public boolean contains(Tree t) {
     if (this == t)
       return true;