Fix possible SIOOBE

import android.content.Context;

import android.text.TextUtils;

import android.util.Log;

import com.android.inputmethod.keyboard.ProximityInfo;

import com.android.inputmethod.latin.SuggestedWords.SuggestedWordInfo;

 * be searched for suggestions and valid words.

 */

public class ExpandableDictionary extends Dictionary {

    private static final String TAG = ExpandableDictionary.class.getSimpleName();

    /**

     * The weight to give to a word if it's length is the same as the number of typed characters.

     */

        // word. We do want however to return the correct case for the right hand side.

        // So we want to squash the case of the left hand side, and preserve that of the right

        // hand side word.

        Node firstWord = searchWord(mRoots, word1.toLowerCase(), 0, null);

        Node secondWord = searchWord(mRoots, word2, 0, null);

        final String word1Lower = word1.toLowerCase();

        if (TextUtils.isEmpty(word1Lower) || TextUtils.isEmpty(word2)) {

            Log.e(TAG, "Invalid bigram pair: " + word1 + ", " + word1Lower + ", " + word2);

            return frequency;

        }

        final Node firstWord = searchWord(mRoots, word1Lower, 0, null);

        final Node secondWord = searchWord(mRoots, word2, 0, null);

        LinkedList<NextWord> bigrams = firstWord.mNGrams;

        if (bigrams == null || bigrams.size() == 0) {

            firstWord.mNGrams = CollectionUtils.newLinkedList();