diff --git a/java/src/com/android/inputmethod/latin/makedict/FusionDictionary.java b/java/src/com/android/inputmethod/latin/makedict/FusionDictionary.java
index 5c80559..e7c7e2b 100644
--- a/java/src/com/android/inputmethod/latin/makedict/FusionDictionary.java
+++ b/java/src/com/android/inputmethod/latin/makedict/FusionDictionary.java
@@ -620,34 +620,34 @@
      * Helper method to find a word in a given branch.
      */
     @SuppressWarnings("unused")
-    public static CharGroup findWordInTree(Node node, final String s) {
+    public static CharGroup findWordInTree(Node node, final String string) {
         int index = 0;
         final StringBuilder checker = DBG ? new StringBuilder() : null;
+        final int[] codePoints = getCodePoints(string);
 
         CharGroup currentGroup;
-        final int codePointCountInS = s.codePointCount(0, s.length());
         do {
-            int indexOfGroup = findIndexOfChar(node, s.codePointAt(index));
+            int indexOfGroup = findIndexOfChar(node, codePoints[index]);
             if (CHARACTER_NOT_FOUND == indexOfGroup) return null;
             currentGroup = node.mData.get(indexOfGroup);
 
-            if (s.length() - index < currentGroup.mChars.length) return null;
+            if (codePoints.length - index < currentGroup.mChars.length) return null;
             int newIndex = index;
-            while (newIndex < s.length() && newIndex - index < currentGroup.mChars.length) {
-                if (currentGroup.mChars[newIndex - index] != s.codePointAt(newIndex)) return null;
+            while (newIndex < codePoints.length && newIndex - index < currentGroup.mChars.length) {
+                if (currentGroup.mChars[newIndex - index] != codePoints[newIndex]) return null;
                 newIndex++;
             }
             index = newIndex;
 
             if (DBG) checker.append(new String(currentGroup.mChars, 0, currentGroup.mChars.length));
-            if (index < codePointCountInS) {
+            if (index < codePoints.length) {
                 node = currentGroup.mChildren;
             }
-        } while (null != node && index < codePointCountInS);
+        } while (null != node && index < codePoints.length);
 
-        if (index < codePointCountInS) return null;
+        if (index < codePoints.length) return null;
         if (!currentGroup.isTerminal()) return null;
-        if (DBG && !s.equals(checker.toString())) return null;
+        if (DBG && !codePoints.equals(checker.toString())) return null;
         return currentGroup;
     }
 
@@ -847,12 +847,12 @@
         @Override
         public Word next() {
             Position currentPos = mPositions.getLast();
-            mCurrentString.setLength(mCurrentString.length() - currentPos.length);
+            mCurrentString.setLength(currentPos.length);
 
             do {
                 if (currentPos.pos.hasNext()) {
                     final CharGroup currentGroup = currentPos.pos.next();
-                    currentPos.length = currentGroup.mChars.length;
+                    currentPos.length = mCurrentString.length();
                     for (int i : currentGroup.mChars)
                         mCurrentString.append(Character.toChars(i));
                     if (null != currentGroup.mChildren) {
@@ -866,7 +866,7 @@
                 } else {
                     mPositions.removeLast();
                     currentPos = mPositions.getLast();
-                    mCurrentString.setLength(mCurrentString.length() - mPositions.getLast().length);
+                    mCurrentString.setLength(mPositions.getLast().length);
                 }
             } while (true);
         }
diff --git a/tests/src/com/android/inputmethod/latin/makedict/BinaryDictIOTests.java b/tests/src/com/android/inputmethod/latin/makedict/BinaryDictIOTests.java
index ade0109..bd87292 100644
--- a/tests/src/com/android/inputmethod/latin/makedict/BinaryDictIOTests.java
+++ b/tests/src/com/android/inputmethod/latin/makedict/BinaryDictIOTests.java
@@ -72,15 +72,12 @@
     private static final FormatSpec.FormatOptions VERSION3_WITH_DYNAMIC_UPDATE =
             new FormatSpec.FormatOptions(3, true /* supportsDynamicUpdate */);
 
-    private static final String[] CHARACTERS = {
-        "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m",
-        "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"
-    };
-
     public BinaryDictIOTests() {
         super();
 
-        final Random random = new Random(123456);
+        final long time = System.currentTimeMillis();
+        Log.e(TAG, "Testing dictionary: seed is " + time);
+        final Random random = new Random(time);
         sWords.clear();
         generateWords(MAX_UNIGRAMS, random);
 
@@ -132,13 +129,16 @@
     /**
      * Generates a random word.
      */
-    private String generateWord(final int value) {
-        final int lengthOfChars = CHARACTERS.length;
+    private String generateWord(final Random random) {
         StringBuilder builder = new StringBuilder("a");
-        long lvalue = Math.abs((long)value);
-        while (lvalue > 0) {
-            builder.append(CHARACTERS[(int)(lvalue % lengthOfChars)]);
-            lvalue /= lengthOfChars;
+        int count = random.nextInt() % 30; // Arbitrarily 30 chars max
+        while (count > 0) {
+            final long r = Math.abs(random.nextInt());
+            if (r < 0) continue;
+            // Don't insert 0~20, but insert any other code point.
+            // Code points are in the range 0~0x10FFFF.
+            builder.appendCodePoint((int)(20 + r % (0x10FFFF - 20)));
+            --count;
         }
         return builder.toString();
     }
@@ -146,7 +146,7 @@
     private void generateWords(final int number, final Random random) {
         final Set<String> wordSet = CollectionUtils.newHashSet();
         while (wordSet.size() < number) {
-            wordSet.add(generateWord(random.nextInt()));
+            wordSet.add(generateWord(random));
         }
         sWords.addAll(wordSet);
     }
@@ -555,7 +555,7 @@
         // Test a word that isn't contained within the dictionary.
         final Random random = new Random((int)System.currentTimeMillis());
         for (int i = 0; i < 1000; ++i) {
-            final String word = generateWord(random.nextInt());
+            final String word = generateWord(random);
             if (sWords.indexOf(word) != -1) continue;
             runGetTerminalPosition(buffer, word, i, false);
         }
diff --git a/tools/dicttool/tests/com/android/inputmethod/latin/makedict/FusionDictionaryTest.java b/tools/dicttool/tests/com/android/inputmethod/latin/makedict/FusionDictionaryTest.java
new file mode 100644
index 0000000..fe3781d
--- /dev/null
+++ b/tools/dicttool/tests/com/android/inputmethod/latin/makedict/FusionDictionaryTest.java
@@ -0,0 +1,114 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.inputmethod.latin.makedict;
+
+import com.android.inputmethod.latin.makedict.FusionDictionary;
+import com.android.inputmethod.latin.makedict.FusionDictionary.CharGroup;
+import com.android.inputmethod.latin.makedict.FusionDictionary.DictionaryOptions;
+import com.android.inputmethod.latin.makedict.FusionDictionary.Node;
+import com.android.inputmethod.latin.makedict.Word;
+
+import junit.framework.TestCase;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Random;
+
+/**
+ * Unit tests for BinaryDictInputOutput.
+ */
+public class FusionDictionaryTest extends TestCase {
+    private static final ArrayList<String> sWords = new ArrayList<String>();
+    private static final int MAX_UNIGRAMS = 1000;
+
+    private void prepare(final long seed) {
+        System.out.println("Seed is " + seed);
+        final Random random = new Random(seed);
+        sWords.clear();
+        generateWords(MAX_UNIGRAMS, random);
+    }
+
+    /**
+     * Generates a random word.
+     */
+    private String generateWord(final Random random) {
+        StringBuilder builder = new StringBuilder("a");
+        int count = random.nextInt() % 30;
+        while (count > 0) {
+            final long r = Math.abs(random.nextInt());
+            if (r < 0) continue;
+            // Don't insert 0~20, but insert any other code point.
+            // Code points are in the range 0~0x10FFFF.
+            if (builder.length() < 7)
+                builder.appendCodePoint((int)(20 +r % (0x10FFFF - 20)));
+            --count;
+        }
+        if (builder.length() == 1) return generateWord(random);
+        return builder.toString();
+    }
+
+    private void generateWords(final int number, final Random random) {
+        while (sWords.size() < number) {
+            sWords.add(generateWord(random));
+        }
+    }
+
+    private void checkDictionary(final FusionDictionary dict, final ArrayList<String> words,
+            int limit) {
+        assertNotNull(dict);
+        for (final String word : words) {
+            if (--limit < 0) return;
+            final CharGroup cg = FusionDictionary.findWordInTree(dict.mRoot, word);
+            if (null == cg) {
+                System.out.println("word " + dumpWord(word));
+                dumpDict(dict);
+            }
+            assertNotNull(cg);
+        }
+    }
+
+    private String dumpWord(final String word) {
+        final StringBuilder sb = new StringBuilder("");
+        for (int i = 0; i < word.length(); i = word.offsetByCodePoints(i, 1)) {
+            sb.append(word.codePointAt(i));
+            sb.append(" ");
+        }
+        return sb.toString();
+    }
+
+    private void dumpDict(final FusionDictionary dict) {
+        for (Word w : dict) {
+            System.out.println("Word " + dumpWord(w.mWord));
+        }
+    }
+
+    // Test the flattened array contains the expected number of nodes, and
+    // that it does not contain any duplicates.
+    public void testFusion() {
+        final FusionDictionary dict = new FusionDictionary(new Node(),
+                new DictionaryOptions(new HashMap<String, String>(),
+                        false /* germanUmlautProcessing */, false /* frenchLigatureProcessing */));
+        final long time = System.currentTimeMillis();
+        prepare(time);
+        for (int i = 0; i < sWords.size(); ++i) {
+            System.out.println("Adding in pos " + i + " : " + dumpWord(sWords.get(i)));
+            dict.add(sWords.get(i), 180, null, false);
+            dumpDict(dict);
+            checkDictionary(dict, sWords, i);
+        }
+    }
+}