SearchService#canMatch takes into consideration the alias filter (#55120)

Co-authored-by: Elastic Machine <[email protected]>

Author: scampi

server/src/main/java/org/elasticsearch/search/SearchService.java

@@ -1116,17 +1116,21 @@ public CanMatchResponse canMatch(ShardSearchRequest request) throws IOException
         // we don't want to use the reader wrapper since it could run costly operations
         // and we can afford false positives.
         try (Engine.Searcher searcher = indexShard.acquireCanMatchSearcher()) {
+            final boolean aliasFilterCanMatch = request.getAliasFilter()
+                .getQueryBuilder() instanceof MatchNoneQueryBuilder == false;
             QueryShardContext context = indexService.newQueryShardContext(request.shardId().id(), searcher,
                 request::nowInMillis, request.getClusterAlias());
             Rewriteable.rewrite(request.getRewriteable(), context, false);
             FieldSortBuilder sortBuilder = FieldSortBuilder.getPrimaryFieldSortOrNull(request.source());
             MinAndMax<?> minMax = sortBuilder != null ? FieldSortBuilder.getMinMaxOrNull(context, sortBuilder) : null;
             if (canRewriteToMatchNone(request.source())) {
                 QueryBuilder queryBuilder = request.source().query();
-                return new CanMatchResponse(queryBuilder instanceof MatchNoneQueryBuilder == false, minMax);
+                return new CanMatchResponse(
+                    aliasFilterCanMatch && queryBuilder instanceof MatchNoneQueryBuilder == false, minMax
+                );
             }
             // null query means match_all
-            return new CanMatchResponse(true, minMax);
+            return new CanMatchResponse(aliasFilterCanMatch, minMax);
         }
     }
 

server/src/test/java/org/elasticsearch/search/SearchServiceTests.java

@@ -673,6 +673,16 @@ public void testCanMatch() throws IOException, InterruptedException {
         ShardSearchRequest request = new ShardSearchRequest(OriginalIndices.NONE, searchRequest, indexShard.shardId(), 1,
             new AliasFilter(null, Strings.EMPTY_ARRAY), 1.0f, -1, null, null);
 
+        assertAcked(
+            client().admin().indices().prepareAliases()
+                .addAlias("index", "alias", new MatchNoneQueryBuilder())
+                .get()
+        );
+
+        searchRequest.source(new SearchSourceBuilder().query(new MatchAllQueryBuilder()));
+        assertFalse(service.canMatch(new ShardSearchRequest(OriginalIndices.NONE, searchRequest, indexShard.shardId(), 1,
+            new AliasFilter(new MatchNoneQueryBuilder(), "alias"), 1f, -1, null, null)).canMatch());
+
         CountDownLatch latch = new CountDownLatch(1);
         SearchShardTask task = new SearchShardTask(123L, "", "", "", null, Collections.emptyMap());
         service.executeQueryPhase(request, task, new ActionListener<SearchPhaseResult>() {