From 4c47daa8d608b9f61fde57fcf452fe8bee9cdd7a Mon Sep 17 00:00:00 2001
From: Yannick Welsch <yannick@welsch.lu>
Date: Wed, 20 Apr 2022 08:58:19 +0200
Subject: [PATCH] Rewrite match_all inside must_not (#85999)

A must_not with a match_all clause inside a bool query is currently not rewritten to a match_none query. This means that running a boolean query with "must_not":[{"terms":{"_tier":["data_frozen","data_cold"]}] is currently not rewritten as match_none on a cold/frozen tier node.
---
 docs/changelog/85999.yaml                             |  5 +++++
 .../org/elasticsearch/upgrades/QueryBuilderBWCIT.java |  5 +++--
 .../elasticsearch/index/query/BoolQueryBuilder.java   | 11 ++++-------
 .../index/query/BoolQueryBuilderTests.java            |  6 ++++++
 4 files changed, 18 insertions(+), 9 deletions(-)
 create mode 100644 docs/changelog/85999.yaml

diff --git a/docs/changelog/85999.yaml b/docs/changelog/85999.yaml
new file mode 100644
index 000000000000..1fa1f2fd034b
--- /dev/null
+++ b/docs/changelog/85999.yaml
@@ -0,0 +1,5 @@
+pr: 85999
+summary: Rewrite `match_all` inside `must_not`
+area: Search
+type: bug
+issues: []
diff --git a/qa/full-cluster-restart/src/test/java/org/elasticsearch/upgrades/QueryBuilderBWCIT.java b/qa/full-cluster-restart/src/test/java/org/elasticsearch/upgrades/QueryBuilderBWCIT.java
index ff27ecfc3851..129030f73113 100644
--- a/qa/full-cluster-restart/src/test/java/org/elasticsearch/upgrades/QueryBuilderBWCIT.java
+++ b/qa/full-cluster-restart/src/test/java/org/elasticsearch/upgrades/QueryBuilderBWCIT.java
@@ -21,6 +21,7 @@ import org.elasticsearch.index.query.BoolQueryBuilder;
 import org.elasticsearch.index.query.ConstantScoreQueryBuilder;
 import org.elasticsearch.index.query.DisMaxQueryBuilder;
 import org.elasticsearch.index.query.MatchAllQueryBuilder;
+import org.elasticsearch.index.query.MatchNoneQueryBuilder;
 import org.elasticsearch.index.query.MatchPhraseQueryBuilder;
 import org.elasticsearch.index.query.MatchQueryBuilder;
 import org.elasticsearch.index.query.Operator;
@@ -84,10 +85,10 @@ public class QueryBuilderBWCIT extends AbstractFullClusterRestartTestCase {
             """, new RangeQueryBuilder("long_field").from(1).to(9));
         addCandidate(
             """
-                "bool": { "must_not": [{"match_all": {}}], "must": [{"match_all": {}}], "filter": [{"match_all": {}}], \
+                "bool": { "must_not": [{"match_none": {}}], "must": [{"match_all": {}}], "filter": [{"match_all": {}}], \
                 "should": [{"match_all": {}}]}
                 """,
-            new BoolQueryBuilder().mustNot(new MatchAllQueryBuilder())
+            new BoolQueryBuilder().mustNot(new MatchNoneQueryBuilder())
                 .must(new MatchAllQueryBuilder())
                 .filter(new MatchAllQueryBuilder())
                 .should(new MatchAllQueryBuilder())
diff --git a/server/src/main/java/org/elasticsearch/index/query/BoolQueryBuilder.java b/server/src/main/java/org/elasticsearch/index/query/BoolQueryBuilder.java
index cb338fecc7f3..cf5a7fe58f4f 100644
--- a/server/src/main/java/org/elasticsearch/index/query/BoolQueryBuilder.java
+++ b/server/src/main/java/org/elasticsearch/index/query/BoolQueryBuilder.java
@@ -29,9 +29,7 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
-import java.util.Optional;
 import java.util.function.Consumer;
-import java.util.stream.Stream;
 
 import static org.elasticsearch.common.lucene.search.Queries.fixNegativeQueryIfNeeded;
 import static org.elasticsearch.search.SearchModule.INDICES_MAX_NESTED_DEPTH_SETTING;
@@ -385,11 +383,10 @@ public class BoolQueryBuilder extends AbstractQueryBuilder<BoolQueryBuilder> {
         }
 
         // lets do some early termination and prevent any kind of rewriting if we have a mandatory query that is a MatchNoneQueryBuilder
-        Optional<QueryBuilder> any = Stream.concat(newBuilder.mustClauses.stream(), newBuilder.filterClauses.stream())
-            .filter(b -> b instanceof MatchNoneQueryBuilder)
-            .findAny();
-        if (any.isPresent()) {
-            return any.get();
+        if (newBuilder.mustClauses.stream().anyMatch(b -> b instanceof MatchNoneQueryBuilder)
+            || newBuilder.filterClauses.stream().anyMatch(b -> b instanceof MatchNoneQueryBuilder)
+            || newBuilder.mustNotClauses.stream().anyMatch(b -> b instanceof MatchAllQueryBuilder)) {
+            return new MatchNoneQueryBuilder();
         }
 
         if (changed) {
diff --git a/server/src/test/java/org/elasticsearch/index/query/BoolQueryBuilderTests.java b/server/src/test/java/org/elasticsearch/index/query/BoolQueryBuilderTests.java
index eaf2090cad7a..bd3e5f53b623 100644
--- a/server/src/test/java/org/elasticsearch/index/query/BoolQueryBuilderTests.java
+++ b/server/src/test/java/org/elasticsearch/index/query/BoolQueryBuilderTests.java
@@ -425,6 +425,12 @@ public class BoolQueryBuilderTests extends AbstractQueryTestCase<BoolQueryBuilde
         boolQueryBuilder = new BoolQueryBuilder();
         rewritten = Rewriteable.rewrite(boolQueryBuilder, createSearchExecutionContext());
         assertNotEquals(new MatchNoneQueryBuilder(), rewritten);
+
+        boolQueryBuilder = new BoolQueryBuilder();
+        boolQueryBuilder.filter(new TermQueryBuilder(TEXT_FIELD_NAME, "bar"));
+        boolQueryBuilder.mustNot(new WrapperQueryBuilder(new WrapperQueryBuilder(new MatchAllQueryBuilder().toString()).toString()));
+        rewritten = boolQueryBuilder.rewrite(createSearchExecutionContext());
+        assertEquals(new MatchNoneQueryBuilder(), rewritten);
     }
 
     @Override