From c9e267f9481c9631d9112411a6473db41230ec53 Mon Sep 17 00:00:00 2001
From: Michael McCandless <mikemccand@apache.org>
Date: Fri, 19 Jun 2015 19:54:02 +0000
Subject: [PATCH] LUCENE-6591: never write a negative vlong

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1686495 13f79535-47bb-0310-9956-ffa450edef68
---
 lucene/CHANGES.txt                                   |  3 +++
 .../src/java/org/apache/lucene/store/DataOutput.java | 12 +++++++-----
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/lucene/CHANGES.txt b/lucene/CHANGES.txt
index fb1edea43b6..0f3fdffe418 100644
--- a/lucene/CHANGES.txt
+++ b/lucene/CHANGES.txt
@@ -158,6 +158,9 @@ Bug fixes
 * LUCENE-6593: Fixed ToChildBlockJoinQuery's scorer to not refuse to advance
   to a document that belongs to the parent space. (Adrien Grand)
 
+* LUCENE-6591: Never write a negative vLong (Robert Muir, Ryan Ernst,
+  Adrien Grand, Mike McCandless)
+
 Changes in Runtime Behavior
 
 * LUCENE-6501: The subreader structure in ParallelCompositeReader
diff --git a/lucene/core/src/java/org/apache/lucene/store/DataOutput.java b/lucene/core/src/java/org/apache/lucene/store/DataOutput.java
index 4daf284be17..efdba774694 100644
--- a/lucene/core/src/java/org/apache/lucene/store/DataOutput.java
+++ b/lucene/core/src/java/org/apache/lucene/store/DataOutput.java
@@ -221,12 +221,14 @@ public abstract class DataOutput {
    * @see DataInput#readVLong()
    */
   public final void writeVLong(long i) throws IOException {
-    assert i >= 0L;
-    writeNegativeVLong(i);
+    if (i < 0) {
+      throw new IllegalArgumentException("cannot write negative vLong (got: " + i + ")");
+    }
+    writeSignedVLong(i);
   }
 
-  // write a pontentially negative vLong
-  private void writeNegativeVLong(long i) throws IOException {
+  // write a potentially negative vLong
+  private void writeSignedVLong(long i) throws IOException {
     while ((i & ~0x7FL) != 0L) {
       writeByte((byte)((i & 0x7FL) | 0x80L));
       i >>>= 7;
@@ -241,7 +243,7 @@ public abstract class DataOutput {
    * @see DataInput#readZLong()
    */
   public final void writeZLong(long i) throws IOException {
-    writeNegativeVLong(BitUtil.zigZagEncode(i));
+    writeSignedVLong(BitUtil.zigZagEncode(i));
   }
 
   /** Writes a string.