Feedback.

Author: wu-hui

firebase-firestore/src/main/java/com/google/firebase/firestore/local/LocalDocumentsView.java

@@ -91,8 +91,11 @@ IndexManager getIndexManager() {
    */
   Document getDocument(DocumentKey key) {
     Mutation overlay = documentOverlayCache.getOverlay(key);
-    MutableDocument document = overlay instanceof PatchMutation ?
-             remoteDocumentCache.get(key) :  MutableDocument.newInvalidDocument(key);
+    MutableDocument document =
+        (overlay == null || overlay instanceof PatchMutation)
+            ? remoteDocumentCache.get(key)
+            : MutableDocument.newInvalidDocument(key);
+    if (overlay != null) {
       overlay.applyToLocalView(document, null, Timestamp.now());
     }
 

firebase-firestore/src/main/java/com/google/firebase/firestore/local/SQLiteRemoteDocumentCache.java

@@ -166,7 +166,7 @@ public Map<DocumentKey, MutableDocument> getAll(
     if (collections.isEmpty()) {
       return Collections.emptyMap();
     } else if (BINDS_PER_STATEMENT * collections.size() < SQLitePersistence.MAX_ARGS) {
-      return getAll(collections, offset, limit, new HashSet<>());
+      return getAll(collections, offset, limit, Collections.emptySet());
     } else {
       // We need to fan out our collection scan since SQLite only supports 999 binds per statement.
       Map<DocumentKey, MutableDocument> results = new HashMap<>();