Index: lucene/src/java/org/apache/lucene/util/fst/Builder.java
===================================================================
--- lucene/src/java/org/apache/lucene/util/fst/Builder.java	(revision 1143420)
+++ lucene/src/java/org/apache/lucene/util/fst/Builder.java	(working copy)
@@ -108,10 +108,9 @@
     return dedupHash == null ? 0 : fst.nodeCount;
   }
 
-  private CompiledNode compileNode(UnCompiledNode<T> n) throws IOException {
-
+  private CompiledNode compileNode(UnCompiledNode<T> n, int tailLength) throws IOException {
     final int address;
-    if (dedupHash != null) {
+    if (dedupHash != null && tailLength < 10) {
       if (n.numArcs == 0) {
         address = fst.addNode(n);
       } else {
@@ -186,7 +185,7 @@
       } else {
 
         if (minSuffixCount2 != 0) {
-          compileAllTargets(node);
+          compileAllTargets(node, lastInput.length-idx);
         }
         final T nextFinalOutput = node.output;
 
@@ -202,7 +201,7 @@
           // compile any targets that were previously
           // undecided:
           parent.replaceLast(lastInput.ints[lastInput.offset + idx-1],
-                             compileNode(node),
+                             compileNode(node, 1+lastInput.length-idx),
                              nextFinalOutput,
                              isFinal);
         } else {
@@ -393,22 +392,23 @@
         // empty string got pruned
         return null;
       } else {
-        fst.finish(compileNode(frontier[0]).address);
+        // nocommit
+        fst.finish(compileNode(frontier[0], 0).address);
         //System.out.println("compile addr = " + fst.getStartNode());
         return fst;
       }
     } else {
       if (minSuffixCount2 != 0) {
-        compileAllTargets(frontier[0]);
+        compileAllTargets(frontier[0], 1);
       }
       //System.out.println("NOW: " + frontier[0].numArcs);
-      fst.finish(compileNode(frontier[0]).address);
+      fst.finish(compileNode(frontier[0], 0).address);
     }
     
     return fst;
   }
 
-  private void compileAllTargets(UnCompiledNode<T> node) throws IOException {
+  private void compileAllTargets(UnCompiledNode<T> node, int tailLength) throws IOException {
     for(int arcIdx=0;arcIdx<node.numArcs;arcIdx++) {
       final Arc<T> arc = node.arcs[arcIdx];
       if (!arc.target.isCompiled()) {
@@ -418,7 +418,7 @@
           //System.out.println("seg=" + segment + "        FORCE final arc=" + (char) arc.label);
           arc.isFinal = n.isFinal = true;
         }
-        arc.target = compileNode(n);
+        arc.target = compileNode(n, tailLength-1);
       }
     }
   }