Get TermVectorResponses for like and unlike items in separate requests, so we don't have to validate responses afterwards.

Relates to #14944

core/src/main/java/org/elasticsearch/index/query/MoreLikeThisQueryBuilder.java

@@ -861,14 +861,14 @@ public class MoreLikeThisQueryBuilder extends AbstractQueryBuilder<MoreLikeThisQ
         }
 
         // fetching the items with multi-termvectors API
-        MultiTermVectorsResponse responses = fetchResponse(context.getClient(), likeItems, unlikeItems, SearchContext.current());
-
+        MultiTermVectorsResponse likeItemsResponse = fetchResponse(context.getClient(), likeItems);
         // getting the Fields for liked items
-        mltQuery.setLikeText(getFieldsFor(responses, likeItems));
+        mltQuery.setLikeText(getFieldsFor(likeItemsResponse));
 
         // getting the Fields for unliked items
         if (unlikeItems.length > 0) {
-            org.apache.lucene.index.Fields[] unlikeFields = getFieldsFor(responses, unlikeItems);
+            MultiTermVectorsResponse unlikeItemsResponse = fetchResponse(context.getClient(), unlikeItems);
+            org.apache.lucene.index.Fields[] unlikeFields = getFieldsFor(unlikeItemsResponse);
             if (unlikeFields.length > 0) {
                 mltQuery.setUnlikeText(unlikeFields);
             }
@@ -907,30 +907,19 @@ public class MoreLikeThisQueryBuilder extends AbstractQueryBuilder<MoreLikeThisQ
         }
     }
 
-    private MultiTermVectorsResponse fetchResponse(Client client, Item[] likeItems, @Nullable Item[] unlikeItems,
-                                                   SearchContext searchContext) throws IOException {
+    private MultiTermVectorsResponse fetchResponse(Client client, Item[] items) throws IOException {
         MultiTermVectorsRequest request = new MultiTermVectorsRequest();
-        for (Item item : likeItems) {
-            request.add(item.toTermVectorsRequest());
-        }
-        for (Item item : unlikeItems) {
+        for (Item item : items) {
             request.add(item.toTermVectorsRequest());
         }
+
         return client.multiTermVectors(request).actionGet();
     }
 
-    private static Fields[] getFieldsFor(MultiTermVectorsResponse responses, Item[] items) throws IOException {
+    private static Fields[] getFieldsFor(MultiTermVectorsResponse responses) throws IOException {
         List<Fields> likeFields = new ArrayList<>();
 
-        Set<Item> selectedItems = new HashSet<>();
-        for (Item request : items) {
-            selectedItems.add(new Item(request.index(), request.type(), request.id()));
-        }
-
         for (MultiTermVectorsItemResponse response : responses) {
-            if (!hasResponseFromRequest(response, selectedItems)) {
-                continue;
-            }
             if (response.isFailed()) {
                 continue;
             }

core/src/test/java/org/elasticsearch/search/morelikethis/MoreLikeThisIT.java

@@ -145,6 +145,32 @@ public class MoreLikeThisIT extends ESIntegTestCase {
         assertThat(response.getHits().getAt(0).id(), equalTo("3"));
     }
 
+    // Issue #14944
+    public void testMoreLikeThisWithAliasesInLikeDocuments() throws Exception {
+        String indexName = "foo";
+        String aliasName = "foo_name";
+        String typeName = "bar";
+
+        String mapping = XContentFactory.jsonBuilder().startObject().startObject("bar")
+                .startObject("properties")
+                .endObject()
+                .endObject().endObject().string();
+        client().admin().indices().prepareCreate(indexName).addMapping(typeName, mapping).execute().actionGet();
+        client().admin().indices().aliases(indexAliasesRequest().addAlias(aliasName, indexName)).actionGet();
+
+        assertThat(ensureGreen(), equalTo(ClusterHealthStatus.GREEN));
+
+        client().index(indexRequest(indexName).type(typeName).id("1").source(jsonBuilder().startObject().field("text", "elasticsearch index").endObject())).actionGet();
+        client().index(indexRequest(indexName).type(typeName).id("2").source(jsonBuilder().startObject().field("text", "lucene index").endObject())).actionGet();
+        client().index(indexRequest(indexName).type(typeName).id("3").source(jsonBuilder().startObject().field("text", "elasticsearch index").endObject())).actionGet();
+        refresh(indexName);
+
+        SearchResponse response = client().prepareSearch().setQuery(
+                new MoreLikeThisQueryBuilder(null, new Item[] {new Item(aliasName, typeName, "1")}).minTermFreq(1).minDocFreq(1)).get();
+        assertHitCount(response, 2L);
+        assertThat(response.getHits().getAt(0).id(), equalTo("3"));
+    }
+
     public void testMoreLikeThisIssue2197() throws Exception {
         Client client = client();
         String mapping = XContentFactory.jsonBuilder().startObject().startObject("bar")
@@ -564,6 +590,7 @@ public class MoreLikeThisIT extends ESIntegTestCase {
                     .maxQueryTerms(100)
                     .include(true)
                     .minimumShouldMatch("0%");
+
             response = client().prepareSearch("test").setTypes("type1").setQuery(mltQuery).get();
             assertSearchResponse(response);
             assertHitCount(response, numFields - (i + 1));