Add version support for inner hits in field collapsing (#27822)

core/src/main/java/org/elasticsearch/action/search/ExpandSearchPhase.java

@@ -165,6 +165,7 @@ private SearchSourceBuilder buildExpandSearchSourceBuilder(InnerHitBuilder optio
         }
         groupSource.explain(options.isExplain());
         groupSource.trackScores(options.isTrackScores());
+        groupSource.version(options.isVersion());
         return groupSource;
     }
 }

core/src/test/java/org/elasticsearch/action/search/ExpandSearchPhaseTests.java

@@ -20,7 +20,6 @@
 package org.elasticsearch.action.search;
 
 import org.elasticsearch.action.ActionListener;
-import org.elasticsearch.action.support.IndicesOptions;
 import org.elasticsearch.common.document.DocumentField;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.text.Text;
@@ -248,6 +247,8 @@ public void run() throws IOException {
 
     public void testExpandRequestOptions() throws IOException {
         MockSearchPhaseContext mockSearchPhaseContext = new MockSearchPhaseContext(1);
+        boolean version = randomBoolean();
+
         mockSearchPhaseContext.searchTransport = new SearchTransportService(
             Settings.builder().put("search.remote.connect", false).build(), null, null) {
 
@@ -256,13 +257,14 @@ void sendExecuteMultiSearch(MultiSearchRequest request, SearchTask task, ActionL
                 final QueryBuilder postFilter = QueryBuilders.existsQuery("foo");
                 assertTrue(request.requests().stream().allMatch((r) -> "foo".equals(r.preference())));
                 assertTrue(request.requests().stream().allMatch((r) -> "baz".equals(r.routing())));
+                assertTrue(request.requests().stream().allMatch((r) -> version == r.source().version()));
                 assertTrue(request.requests().stream().allMatch((r) -> postFilter.equals(r.source().postFilter())));
             }
         };
         mockSearchPhaseContext.getRequest().source(new SearchSourceBuilder()
             .collapse(
                 new CollapseBuilder("someField")
-                    .setInnerHits(new InnerHitBuilder().setName("foobarbaz"))
+                    .setInnerHits(new InnerHitBuilder().setName("foobarbaz").setVersion(version))
             )
             .postFilter(QueryBuilders.existsQuery("foo")))
             .preference("foobar")

rest-api-spec/src/main/resources/rest-api-spec/test/search/110_field_collapsing.yml

@@ -7,36 +7,48 @@ setup:
           index:  test
           type:   test
           id:     1
+          version_type: external
+          version: 11
           body:   { numeric_group: 1, sort: 10 }
   - do:
       index:
           index:  test
           type:   test
           id:     2
+          version_type: external
+          version: 22
           body:   { numeric_group: 1, sort: 6 }
   - do:
       index:
           index:  test
           type:   test
           id:     3
+          version_type: external
+          version: 33
           body:   { numeric_group: 1, sort: 24 }
   - do:
       index:
           index:  test
           type:   test
           id:     4
+          version_type: external
+          version: 44
           body:   { numeric_group: 25, sort: 10 }
   - do:
       index:
           index:  test
           type:   test
           id:     5
+          version_type: external
+          version: 55
           body:   { numeric_group: 25, sort: 5 }
   - do:
       index:
           index:  test
           type:   test
           id:     6
+          version_type: external
+          version: 66
           body:   { numeric_group: 3, sort: 36 }
   - do:
       indices.refresh:
@@ -322,3 +334,56 @@ setup:
   - match: { hits.hits.2.inner_hits.sub_hits_desc.hits.total: 2 }
   - length: { hits.hits.2.inner_hits.sub_hits_desc.hits.hits: 1 }
   - match: { hits.hits.2.inner_hits.sub_hits_desc.hits.hits.0._id: "4" }
+
+---
+"field collapsing, inner_hits and version":
+
+  - skip:
+      version: " - 6.99.99"
+      reason:  "bug fixed in 7.0.0"
+
+  - do:
+      search:
+        index: test
+        type:  test
+        body:
+          collapse: { field: numeric_group, inner_hits: { name: sub_hits, version: true, size: 2, sort: [{ sort: asc }] } }
+          sort: [{ sort: desc }]
+          version: true
+
+  - match: { hits.total: 6 }
+  - length: { hits.hits: 3 }
+  - match: { hits.hits.0._index: test }
+  - match: { hits.hits.0._type: test }
+  - match: { hits.hits.0.fields.numeric_group: [3] }
+  - match: { hits.hits.0.sort: [36] }
+  - match: { hits.hits.0._id: "6" }
+  - match: { hits.hits.0._version: 66 }
+  - match: { hits.hits.0.inner_hits.sub_hits.hits.total: 1 }
+  - length: { hits.hits.0.inner_hits.sub_hits.hits.hits: 1 }
+  - match: { hits.hits.0.inner_hits.sub_hits.hits.hits.0._id: "6" }
+  - match: { hits.hits.0.inner_hits.sub_hits.hits.hits.0._version: 66 }
+  - match: { hits.hits.1._index: test }
+  - match: { hits.hits.1._type: test }
+  - match: { hits.hits.1.fields.numeric_group: [1] }
+  - match: { hits.hits.1.sort: [24] }
+  - match: { hits.hits.1._id: "3" }
+  - match: { hits.hits.1._version: 33 }
+  - match: { hits.hits.1.inner_hits.sub_hits.hits.total: 3 }
+  - length: { hits.hits.1.inner_hits.sub_hits.hits.hits: 2 }
+  - match: { hits.hits.1.inner_hits.sub_hits.hits.hits.0._id: "2" }
+  - match: { hits.hits.1.inner_hits.sub_hits.hits.hits.0._version: 22 }
+  - match: { hits.hits.1.inner_hits.sub_hits.hits.hits.1._id: "1" }
+  - match: { hits.hits.1.inner_hits.sub_hits.hits.hits.1._version: 11 }
+  - match: { hits.hits.2._index: test }
+  - match: { hits.hits.2._type: test }
+  - match: { hits.hits.2.fields.numeric_group: [25] }
+  - match: { hits.hits.2.sort: [10] }
+  - match: { hits.hits.2._id: "4" }
+  - match: { hits.hits.2._version: 44 }
+  - match: { hits.hits.2.inner_hits.sub_hits.hits.total: 2 }
+  - length: { hits.hits.2.inner_hits.sub_hits.hits.hits: 2 }
+  - match: { hits.hits.2.inner_hits.sub_hits.hits.hits.0._id: "5" }
+  - match: { hits.hits.2.inner_hits.sub_hits.hits.hits.0._version: 55 }
+  - match: { hits.hits.2.inner_hits.sub_hits.hits.hits.1._id: "4" }
+  - match: { hits.hits.2.inner_hits.sub_hits.hits.hits.1._version: 44 }