From a11457b4e636f939bf1c1592c6378627ec4dd1e3 Mon Sep 17 00:00:00 2001
From: Greg Miller <gsmiller@gmail.com>
Date: Sat, 7 Aug 2021 10:20:49 -0700
Subject: [PATCH] LUCENE-10047: Fix value de-duping check in
 LongValueFacetCounts and RangeFacetCounts (#237)

---
 lucene/CHANGES.txt                                        | 3 +++
 .../org/apache/lucene/facet/LongValueFacetCounts.java     | 8 ++++----
 .../org/apache/lucene/facet/range/RangeFacetCounts.java   | 4 ++--
 3 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/lucene/CHANGES.txt b/lucene/CHANGES.txt
index 2605de8be51..4e1a8ff572c 100644
--- a/lucene/CHANGES.txt
+++ b/lucene/CHANGES.txt
@@ -281,6 +281,9 @@ Bug fixes
 * LUCENE-9823: Prevent unsafe rewrites for SynonymQuery and CombinedFieldQuery. Before, rewriting
   could slightly change the scoring when weights were specified. (Naoto Minami via Julie Tibshirani)
 
+* LUCENE-10047: Fix a value de-duping bug in LongValueFacetCounts and RangeFacetCounts
+  (Greg Miller)
+
 Changes in Backwards Compatibility Policy
 
 * LUCENE-9904: regenerated UAX29URLEmailTokenizer and the corresponding analyzer with up-to-date top
diff --git a/lucene/facet/src/java/org/apache/lucene/facet/LongValueFacetCounts.java b/lucene/facet/src/java/org/apache/lucene/facet/LongValueFacetCounts.java
index 864e2265cf2..56e0286a926 100644
--- a/lucene/facet/src/java/org/apache/lucene/facet/LongValueFacetCounts.java
+++ b/lucene/facet/src/java/org/apache/lucene/facet/LongValueFacetCounts.java
@@ -162,11 +162,11 @@ public class LongValueFacetCounts extends Facets {
           if (limit > 0) {
             totCount++;
           }
-          long previousValue = -1;
+          long previousValue = 0;
           for (int i = 0; i < limit; i++) {
             long value = multiValues.nextValue();
             // do not increment the count for duplicate values
-            if (value != previousValue) {
+            if (i == 0 || value != previousValue) {
               increment(value);
               previousValue = value;
             }
@@ -214,11 +214,11 @@ public class LongValueFacetCounts extends Facets {
           if (limit > 0) {
             totCount++;
           }
-          long previousValue = -1;
+          long previousValue = 0;
           for (int i = 0; i < limit; i++) {
             long value = multiValues.nextValue();
             // do not increment the count for duplicate values
-            if (value != previousValue) {
+            if (i == 0 || value != previousValue) {
               increment(value);
               previousValue = value;
             }
diff --git a/lucene/facet/src/java/org/apache/lucene/facet/range/RangeFacetCounts.java b/lucene/facet/src/java/org/apache/lucene/facet/range/RangeFacetCounts.java
index 3f56c78fa3a..fc376c5b0c7 100644
--- a/lucene/facet/src/java/org/apache/lucene/facet/range/RangeFacetCounts.java
+++ b/lucene/facet/src/java/org/apache/lucene/facet/range/RangeFacetCounts.java
@@ -193,10 +193,10 @@ abstract class RangeFacetCounts extends Facets {
               totCount++;
             } else {
               counter.startMultiValuedDoc();
-              long previous = -1;
+              long previous = 0;
               for (int j = 0; j < limit; j++) {
                 long val = mapDocValue(multiValues.nextValue());
-                if (val != previous) {
+                if (j == 0 || val != previous) {
                   counter.addMultiValued(val);
                   previous = val;
                 }