Fix a NPE caused by a null typedWord

bug: 3514797
Change-Id: Ie1056745ded1f848d1e4f70c5344d6969de509b0
diff --git a/java/src/com/android/inputmethod/latin/ExpandableDictionary.java b/java/src/com/android/inputmethod/latin/ExpandableDictionary.java
index b10e7a6..b0bbe6d 100644
--- a/java/src/com/android/inputmethod/latin/ExpandableDictionary.java
+++ b/java/src/com/android/inputmethod/latin/ExpandableDictionary.java
@@ -225,7 +225,7 @@
     /**
      * Returns the word's frequency or -1 if not found
      */
-    public int getWordFrequency(CharSequence word) {
+    protected int getWordFrequency(CharSequence word) {
         Node node = searchNode(mRoots, word, 0, word.length());
         return (node == null) ? -1 : node.mFrequency;
     }
diff --git a/java/src/com/android/inputmethod/latin/LatinIME.java b/java/src/com/android/inputmethod/latin/LatinIME.java
index 646de66..c66cb5f 100644
--- a/java/src/com/android/inputmethod/latin/LatinIME.java
+++ b/java/src/com/android/inputmethod/latin/LatinIME.java
@@ -1427,7 +1427,6 @@
 
     private void saveWordInHistory(CharSequence result) {
         if (mWord.size() <= 1) {
-            mWord.reset();
             return;
         }
         // Skip if result is null. It happens in some edge case.