Index: lucene/core/src/java/org/apache/lucene/store/NIOFSDirectory.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/store/NIOFSDirectory.java	(revision 1511979)
+++ lucene/core/src/java/org/apache/lucene/store/NIOFSDirectory.java	(working copy)
@@ -200,6 +200,9 @@
           }
           bb.limit(limit);
           int i = channel.read(bb, pos);
+          if (i < 0){//be defensive here, even though we checked before hand, something could have changed
+            throw new EOFException("read past EOF: " + this + " off: " + offset + " len: " + len + " pos: " + pos + " limit: " + limit + " end: " + end);
+          }
           pos += i;
           readOffset += i;
           readLength -= i;
Index: lucene/core/src/java/org/apache/lucene/store/SimpleFSDirectory.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/store/SimpleFSDirectory.java	(revision 1511979)
+++ lucene/core/src/java/org/apache/lucene/store/SimpleFSDirectory.java	(working copy)
@@ -155,6 +155,9 @@
               readLength = chunkSize;
             }
             final int i = file.read(b, offset + total, readLength);
+            if (i < 0){//be defensive here, even though we checked before hand, something could have changed
+             throw new EOFException("read past EOF: " + this + " off: " + offset + " len: " + len + " total: " + total + " readLen: " + readLength + " end: " + end);
+            }
             total += i;
           } while (total < len);
         } catch (OutOfMemoryError e) {