Fallback to the included dict if the passed one is invalid

If all dictionaries returned by the dictionary pack are invalid,
then fallback to the dictionary included in the resources for this
locale.

Bug: 5052486
Change-Id: Id875194ca56a74b2ed6f5b0b4fdd55475f6842c8

1 files changed, 15 insertions, 3 deletions

diff --git a/java/src/com/android/inputmethod/latin/DictionaryFactory.java b/java/src/com/android/inputmethod/latin/DictionaryFactory.java
index a35b0f5b0..f0637b8ce 100644
--- a/java/src/com/android/inputmethod/latin/DictionaryFactory.java
+++ b/java/src/com/android/inputmethod/latin/DictionaryFactory.java
@@ -56,8 +56,11 @@ public class DictionaryFactory {
                 BinaryDictionaryGetter.getDictionaryFiles(locale, context, fallbackResId);
         if (null != assetFileList) {
             for (final AssetFileAddress f : assetFileList) {
-                dictList.add(
-                        new BinaryDictionary(context, f.mFilename, f.mOffset, f.mLength, null));
+                final BinaryDictionary binaryDictionary =
+                        new BinaryDictionary(context, f.mFilename, f.mOffset, f.mLength, null);
+                if (binaryDictionary.isValidDictionary()) {
+                    dictList.add(binaryDictionary);
+                }
             }
         }
 
@@ -67,7 +70,16 @@ public class DictionaryFactory {
         if (null == dictList) {
             return new DictionaryCollection();
         } else {
-            return new DictionaryCollection(dictList);
+            if (dictList.isEmpty()) {
+                // The list may be empty if no dictionaries have been added. The getter should not
+                // return an empty list, but if it does we end up here. Likewise, if the files
+                // we found could not be opened by the native code for any reason (format mismatch,
+                // file too big to fit in memory, etc) then we could have an empty list. In this
+                // case we want to fall back on the resource.
+                return new DictionaryCollection(createBinaryDictionary(context, fallbackResId));
+            } else {
+                return new DictionaryCollection(dictList);
+            }
         }
     }