Safe check so we don't move cursor beyond possible pos scope.

Bug: 28278372
Change-Id: I7c66b5229ae3a6a1b99bdf0f02bf1f0b8a1c79b2

packages/DocumentsUI/src/com/android/documentsui/dirlist/Model.java

@@ -163,7 +163,10 @@ public class Model {
 
         mCursor.moveToPosition(-1);
         for (int pos = 0; pos < mCursorCount; ++pos) {
-            mCursor.moveToNext();
+            if (!mCursor.moveToNext()) {
+                Log.e(TAG, "Fail to move cursor to next pos: " + pos);
+                return;
+            }
             positions[pos] = pos;
 
             // Generates a Model ID for a cursor entry that refers to a document. The Model ID is a