Fix a crash when MAX_WORD_LENGTH is too short.

Change-Id: Idcb5aa2685321b8d0ac7d846caecbd1c79e4dd77

java/src/com/android/inputmethod/latin/BinaryDictionary.java

@@ -170,12 +170,12 @@ public class BinaryDictionary extends Dictionary {
                 mOutputChars_bigrams, mFrequencies_bigrams, MAX_WORD_LENGTH, MAX_BIGRAMS,
                 MAX_ALTERNATIVES);
 
-        for (int j = 0; j < count; j++) {
+        for (int j = 0; j < count; ++j) {
             if (mFrequencies_bigrams[j] < 1) break;
-            int start = j * MAX_WORD_LENGTH;
+            final int start = j * MAX_WORD_LENGTH;
             int len = 0;
-            while (mOutputChars_bigrams[start + len] != 0) {
-                len++;
+            while (len <  MAX_WORD_LENGTH && mOutputChars_bigrams[start + len] != 0) {
+                ++len;
             }
             if (len > 0) {
                 callback.addWord(mOutputChars_bigrams, start, len, mFrequencies_bigrams[j],
@@ -204,12 +204,12 @@ public class BinaryDictionary extends Dictionary {
                 mFrequencies, nextLettersFrequencies,
                 nextLettersFrequencies != null ? nextLettersFrequencies.length : 0);
 
-        for (int j = 0; j < count; j++) {
+        for (int j = 0; j < count; ++j) {
             if (mFrequencies[j] < 1) break;
-            int start = j * MAX_WORD_LENGTH;
+            final int start = j * MAX_WORD_LENGTH;
             int len = 0;
-            while (mOutputChars[start + len] != 0) {
-                len++;
+            while (len < MAX_WORD_LENGTH && mOutputChars[start + len] != 0) {
+                ++len;
             }
             if (len > 0) {
                 callback.addWord(mOutputChars, start, len, mFrequencies[j], mDicTypeId,

native/src/bigram_dictionary.cpp

@@ -146,7 +146,7 @@ void BigramDictionary::searchForTerminalNode(int addressLookingFor, int frequenc
         bool firstAddress = true;
         bool haveToSearchAll = true;
 
-        if (depth >= 0) {
+        if (depth < MAX_WORD_LENGTH && depth >= 0) {
             word[depth] = (unsigned short) followingChar;
         }
         pos = followDownBranchAddress; // pos start at count

native/src/defines.h

@@ -50,8 +50,12 @@
 #define SUGGEST_MISSING_CHARACTERS true
 #define SUGGEST_MISSING_CHARACTERS_THRESHOLD 5
 
-#define MAX_WORD_LENGTH_INTERNAL 64
+// This should be greater than or equal to MAX_WORD_LENGTH defined in BinaryDictionary.java
+// This is only used for the size of array. Not to be used in c functions.
+#define MAX_WORD_LENGTH_INTERNAL 48
 
 #define MAX_DEPTH_MULTIPLIER 3
 
+#define min(a,b) ((a)<(b)?(a):(b))
+
 #endif // LATINIME_DEFINES_H

native/src/unigram_dictionary.cpp

@@ -16,8 +16,8 @@
 */
 
 #include <assert.h>
-#include <stdio.h>
 #include <fcntl.h>
+#include <stdio.h>
 #include <string.h>
 
 #define LOG_TAG "LatinIME: unigram_dictionary.cpp"
@@ -78,6 +78,7 @@ int UnigramDictionary::getSuggestions(int *codes, int codesSize, unsigned short
 
 void UnigramDictionary::initSuggestions(int *codes, int codesSize, unsigned short *outWords,
         int *frequencies) {
+    if (DEBUG_DICT) LOGI("initSuggest");
     mFrequencies = frequencies;
     mOutputChars = outWords;
     mInputCodes = codes;
@@ -87,6 +88,7 @@ void UnigramDictionary::initSuggestions(int *codes, int codesSize, unsigned shor
 
 int UnigramDictionary::getSuggestionCandidates(int inputLength, int skipPos,
         int *nextLetters, int nextLettersSize) {
+    if (DEBUG_DICT) LOGI("getSuggestionCandidates");
     int initialPos = 0;
     if (IS_LATEST_DICT_VERSION) {
         initialPos = DICTIONARY_HEADER_SIZE;
@@ -115,6 +117,10 @@ bool UnigramDictionary::addWord(unsigned short *word, int length, int frequency)
         for (int i = 0; i <= length; i++) s[i] = word[i];
         LOGI("Found word = %s, freq = %d : \n", s, frequency);
     }
+    if (length > MAX_WORD_LENGTH) {
+        if (DEBUG_DICT) LOGI("Exceeded max word length.");
+        return false;
+    }
 
     // Find the right insertion point
     int insertAt = 0;
@@ -177,7 +183,8 @@ void UnigramDictionary::getWords(const int initialPos, const int inputLength, co
         int *nextLetters, const int nextLettersSize) {
     int initialPosition = initialPos;
     const int count = Dictionary::getCount(DICT, &initialPosition);
-    getWordsRec(count, initialPosition, 0, inputLength * MAX_DEPTH_MULTIPLIER,
+    getWordsRec(count, initialPosition, 0,
+            min(inputLength * MAX_DEPTH_MULTIPLIER, MAX_WORD_LENGTH),
             mInputLength <= 0, 1, 0, 0, skipPos, nextLetters, nextLettersSize);
 }