From 9cb17b0b7bb6bd820627a08c58ac3a4e64d38379 Mon Sep 17 00:00:00 2001
From: Luca Cavanna <javanna@apache.org>
Date: Wed, 3 May 2023 11:27:33 +0200
Subject: [PATCH] Fix SynonymQuery equals implementation (#12260)

The term member of TermAndBoost used to be a Term instance and became a
BytesRef with #11941, which means its equals impl won't take the field
name into account. The SynonymQuery equals impl needs to be updated
accordingly to take the field into account as well, otherwise synonym
queries with same term and boost across different fields are equal which
is a bug.
---
 .../org/apache/lucene/search/SynonymQuery.java |  6 ++++--
 .../apache/lucene/search/TestSynonymQuery.java | 18 ++++++++++++++++++
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/lucene/core/src/java/org/apache/lucene/search/SynonymQuery.java b/lucene/core/src/java/org/apache/lucene/search/SynonymQuery.java
index ca32a7d7bb8e..7e314870f9c7 100644
--- a/lucene/core/src/java/org/apache/lucene/search/SynonymQuery.java
+++ b/lucene/core/src/java/org/apache/lucene/search/SynonymQuery.java
@@ -113,7 +113,7 @@ public SynonymQuery build() {
    */
   private SynonymQuery(TermAndBoost[] terms, String field) {
     this.terms = Objects.requireNonNull(terms);
-    this.field = field;
+    this.field = Objects.requireNonNull(field);
   }
 
   public List<Term> getTerms() {
@@ -146,7 +146,9 @@ public int hashCode() {
 
   @Override
   public boolean equals(Object other) {
-    return sameClassAs(other) && Arrays.equals(terms, ((SynonymQuery) other).terms);
+    return sameClassAs(other)
+        && field.equals(((SynonymQuery) other).field)
+        && Arrays.equals(terms, ((SynonymQuery) other).terms);
   }
 
   @Override
diff --git a/lucene/core/src/test/org/apache/lucene/search/TestSynonymQuery.java b/lucene/core/src/test/org/apache/lucene/search/TestSynonymQuery.java
index 123307e75f8e..ae026a87367f 100644
--- a/lucene/core/src/test/org/apache/lucene/search/TestSynonymQuery.java
+++ b/lucene/core/src/test/org/apache/lucene/search/TestSynonymQuery.java
@@ -73,6 +73,18 @@ public void testEquals() {
             .addTerm(new Term("field", "c"), 0.2f)
             .addTerm(new Term("field", "d"))
             .build());
+
+    QueryUtils.checkUnequal(
+        new SynonymQuery.Builder("field").addTerm(new Term("field", "a"), 0.4f).build(),
+        new SynonymQuery.Builder("field").addTerm(new Term("field", "b"), 0.4f).build());
+
+    QueryUtils.checkUnequal(
+        new SynonymQuery.Builder("field").addTerm(new Term("field", "a"), 0.2f).build(),
+        new SynonymQuery.Builder("field").addTerm(new Term("field", "a"), 0.4f).build());
+
+    QueryUtils.checkUnequal(
+        new SynonymQuery.Builder("field1").addTerm(new Term("field1", "b"), 0.4f).build(),
+        new SynonymQuery.Builder("field2").addTerm(new Term("field2", "b"), 0.4f).build());
   }
 
   public void testBogusParams() {
@@ -127,6 +139,12 @@ public void testBogusParams() {
         () -> {
           new SynonymQuery.Builder("field1").addTerm(new Term("field1", "a"), -0f);
         });
+
+    expectThrows(
+        NullPointerException.class,
+        () -> new SynonymQuery.Builder(null).addTerm(new Term("field1", "a"), -0f));
+
+    expectThrows(NullPointerException.class, () -> new SynonymQuery.Builder(null).build());
   }
 
   public void testToString() {