Index: lucene/core/src/java/org/apache/lucene/util/PagedBytes.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/util/PagedBytes.java	(revision 1392832)
+++ lucene/core/src/java/org/apache/lucene/util/PagedBytes.java	(working copy)
@@ -516,7 +516,7 @@
       if (currentBlock == null) {
         return 0;
       } else {
-        return blocks.size() * blockSize + upto;
+        return ((long) blocks.size() * blockSize) + upto;
       }
     }
   }