Index: lucene/src/java/org/apache/lucene/store/IndexInput.java
===================================================================
--- lucene/src/java/org/apache/lucene/store/IndexInput.java	(revision 1083087)
+++ lucene/src/java/org/apache/lucene/store/IndexInput.java	(working copy)
@@ -80,11 +80,18 @@
   public int readVInt() throws IOException {
     byte b = readByte();
     int i = b & 0x7F;
-    for (int shift = 7; (b & 0x80) != 0; shift += 7) {
-      b = readByte();
-      i |= (b & 0x7F) << shift;
-    }
-    return i;
+    if ((b & 0x80) == 0) return i;
+    b = readByte();
+    i |= (b & 0x7F) << 7;
+    if ((b & 0x80) == 0) return i;
+    b = readByte();
+    i |= (b & 0x7F) << 14;
+    if ((b & 0x80) == 0) return i;
+    b = readByte();
+    i |= (b & 0x7F) << 21;
+    if ((b & 0x80) == 0) return i;
+    b = readByte();
+    return i | (b & 0x7F) << 28;
   }
 
   /** Reads eight bytes and returns a long.
@@ -99,12 +106,31 @@
    * supported. */
   public long readVLong() throws IOException {
     byte b = readByte();
-    long i = b & 0x7F;
-    for (int shift = 7; (b & 0x80) != 0; shift += 7) {
-      b = readByte();
-      i |= (b & 0x7FL) << shift;
-    }
-    return i;
+    long i = b & 0x7FL;
+    if ((b & 0x80) == 0) return i;
+    b = readByte();
+    i |= (b & 0x7FL) << 7;
+    if ((b & 0x80) == 0) return i;
+    b = readByte();
+    i |= (b & 0x7FL) << 14;
+    if ((b & 0x80) == 0) return i;
+    b = readByte();
+    i |= (b & 0x7FL) << 21;
+    if ((b & 0x80) == 0) return i;
+    b = readByte();
+    i |= (b & 0x7FL) << 28;
+    if ((b & 0x80) == 0) return i;
+    b = readByte();
+    i |= (b & 0x7FL) << 35;
+    if ((b & 0x80) == 0) return i;
+    b = readByte();
+    i |= (b & 0x7FL) << 42;
+    if ((b & 0x80) == 0) return i;
+    b = readByte();
+    i |= (b & 0x7FL) << 49;
+    if ((b & 0x80) == 0) return i;
+    b = readByte();
+    return i | (b & 0x7FL) << 56;
   }
 
   /** Call this if readString should read characters stored