Fix two nasty bugs with surrogate pairs.

The important bug is in findWordInTree. The problem, which is
not obvious, is that we were calling codePointAt() with the
code point index in the string, instead of the char index.
The other bug this change fixes was harmless in the practice,
because it's in the iteration which is only used for debug and
pretty printing purposes. It's very similar in that it would
substract a length in code point to a length in chars and
truncate a StringBuilder at that length, so it would fail in a
quite similar manner. This changes the meaning of the "length"
attribute in Position, but it's clearer this way anyway.

Bug: 8450145
Change-Id: If396f883a9e6449de39351553ba83f5be5bd30f0

1 files changed, 114 insertions, 0 deletions

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 000000000..fe3781d80
--- /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);
+        }
+    }
+}