1 files changed, 18 insertions, 4 deletions

diff --git a/java/src/com/android/inputmethod/latin/Utils.java b/java/src/com/android/inputmethod/latin/Utils.java
index 5059860d7..e980d3a30 100644
--- a/java/src/com/android/inputmethod/latin/Utils.java
+++ b/java/src/com/android/inputmethod/latin/Utils.java
@@ -38,6 +38,7 @@ import java.util.Date;
 
 public class Utils {
     private static final String TAG = Utils.class.getSimpleName();
+    private static final int MINIMUM_SAFETY_NET_CHAR_LENGTH = 4;
     private static boolean DBG = LatinImeLogger.sDBG;
 
     /**
@@ -106,11 +107,18 @@ public class Utils {
         throw new RuntimeException("Can not find input method id for " + packageName);
     }
 
-    public static boolean shouldBlockedBySafetyNetForAutoCorrection(SuggestedWords suggestions) {
+    public static boolean shouldBlockedBySafetyNetForAutoCorrection(SuggestedWords suggestions,
+            Suggest suggest) {
         // Safety net for auto correction.
         // Actually if we hit this safety net, it's actually a bug.
         if (suggestions.size() <= 1 || suggestions.mTypedWordValid) return false;
+        // If user selected aggressive auto correction mode, there is no need to use the safety
+        // net.
+        if (suggest.isAggressiveAutoCorrectionMode()) return false;
         CharSequence typedWord = suggestions.getWord(0);
+        // If the length of typed word is less than MINIMUM_SAFETY_NET_CHAR_LENGTH,
+        // we should not use net because relatively edit distance can be big.
+        if (typedWord.length() < MINIMUM_SAFETY_NET_CHAR_LENGTH) return false;
         CharSequence candidateWord = suggestions.getWord(1);
         final int typedWordLength = typedWord.length();
         final int maxEditDistanceOfNativeDictionary = typedWordLength < 5 ? 2 : typedWordLength / 2;
@@ -120,8 +128,11 @@ public class Utils {
                     + ", " + maxEditDistanceOfNativeDictionary);
         }
         if (distance > maxEditDistanceOfNativeDictionary) {
-            Log.w(TAG, "(Error) The edit distance of this correction exceeds limit. "
-                    + "Turning off auto-correction.");
+            if (DBG) {
+                Log.d(TAG, "Safety net: before = " + typedWord + ", after = " + candidateWord);
+                Log.w(TAG, "(Error) The edit distance of this correction exceeds limit. "
+                        + "Turning off auto-correction.");
+            }
             return true;
         } else {
             return false;
@@ -267,9 +278,12 @@ public class Utils {
     public static double calcNormalizedScore(CharSequence before, CharSequence after, int score) {
         final int beforeLength = before.length();
         final int afterLength = after.length();
+        if (beforeLength == 0 || afterLength == 0) return 0;
         final int distance = editDistance(before, after);
+        // If afterLength < beforeLength, the algorithm is suggesting a word by excessive character
+        // correction.
         final double maximumScore = MAX_INITIAL_SCORE
-                * Math.pow(TYPED_LETTER_MULTIPLIER, beforeLength)
+                * Math.pow(TYPED_LETTER_MULTIPLIER, Math.min(beforeLength, afterLength))
                 * FULL_WORD_MULTIPLYER;
         // add a weight based on edit distance.
         // distance <= max(afterLength, beforeLength) == afterLength,