From d0dd5fadcc90f71864a7a716936e2d4a3ec2f14d Mon Sep 17 00:00:00 2001
From: Robert Muir <rmuir@apache.org>
Date: Sat, 11 Aug 2012 14:31:56 +0000
Subject: [PATCH] Don't allow negatives in the positions file

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1371961 13f79535-47bb-0310-9956-ffa450edef68
---
 lucene/CHANGES.txt                              |  5 +++++
 .../org/apache/lucene/index/CheckIndex.java     | 17 ++++-------------
 2 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/lucene/CHANGES.txt b/lucene/CHANGES.txt
index 7b636380280..7030490cc5c 100644
--- a/lucene/CHANGES.txt
+++ b/lucene/CHANGES.txt
@@ -31,6 +31,11 @@ Bug Fixes
   had a custom Similarity where coord(1,1) != 1F, then the rewritten
   query would be scored differently.  (Robert Muir)
 
+* Don't allow negatives in the positions file. If you have an index
+  from 2.4.0 or earlier with such negative positions, and you already 
+  upgraded to 3.x, then to Lucene 4.0-ALPHA or -BETA, you should run 
+  CheckIndex. If it fails, then you need to upgrade again to 4.0  (Robert Muir)
+
 ======================= Lucene 4.0.0-BETA =======================
 
 New features
diff --git a/lucene/core/src/java/org/apache/lucene/index/CheckIndex.java b/lucene/core/src/java/org/apache/lucene/index/CheckIndex.java
index d71c8e6bf27..3bcf7d17ff2 100644
--- a/lucene/core/src/java/org/apache/lucene/index/CheckIndex.java
+++ b/lucene/core/src/java/org/apache/lucene/index/CheckIndex.java
@@ -822,11 +822,8 @@ public class CheckIndex {
           if (hasPositions) {
             for(int j=0;j<freq;j++) {
               final int pos = postings.nextPosition();
-              // NOTE: pos=-1 is allowed because of ancient bug
-              // (LUCENE-1542) whereby IndexWriter could
-              // write pos=-1 when first token's posInc is 0
 
-              if (pos < -1) {
+              if (pos < 0) {
                 throw new RuntimeException("term " + term + ": doc " + doc + ": pos " + pos + " is out of bounds");
               }
               if (pos < lastPos) {
@@ -919,14 +916,8 @@ public class CheckIndex {
               int lastOffset = 0;
               for(int posUpto=0;posUpto<freq;posUpto++) {
                 final int pos = postings.nextPosition();
-                // NOTE: pos=-1 is allowed because of ancient bug
-                // (LUCENE-1542) whereby IndexWriter could
-                // write pos=-1 when first token's posInc is 0
-                // (separately: analyzers should not give
-                // posInc=0 to first token); also, term
-                // vectors are allowed to return pos=-1 if
-                // they indexed offset but not positions:
-                if (pos < -1) {
+
+                if (pos < 0) {
                   throw new RuntimeException("position " + pos + " is out of bounds");
                 }
                 if (pos < lastPosition) {
@@ -1498,7 +1489,7 @@ public class CheckIndex {
                       int pos = postings.nextPosition();
                       if (postingsPostings != null) {
                         int postingsPos = postingsPostings.nextPosition();
-                        if (pos != -1 && postingsPos != -1 && pos != postingsPos) {
+                        if (terms.hasPositions() && pos != postingsPos) {
                           throw new RuntimeException("vector term=" + term + " field=" + field + " doc=" + j + ": pos=" + pos + " differs from postings pos=" + postingsPos);
                         }
                       }