add test

Author: kkrik-es

rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/indices.create/21_synthetic_source_stored.yml

@@ -411,6 +411,55 @@ index param - nested array within array:
   - match: { hits.hits.0._source.path.to.some.3.id: [ 1000, 2000 ] }
 
 
+---
+index param - nested array within array - disabled second pass:
+  - requires:
+      cluster_features: ["mapper.synthetic_source_keep", "mapper.bwc_workaround_9_0"]
+      reason: requires tracking ignored source
+
+  - do:
+      indices.create:
+        index: test
+        body:
+          settings:
+            index:
+              synthetic_source:
+                enable_second_doc_parsing_pass: false
+          mappings:
+            _source:
+              mode: synthetic
+            properties:
+              name:
+                type: keyword
+              path:
+                properties:
+                  to:
+                    properties:
+                      some:
+                        synthetic_source_keep: arrays
+                        properties:
+                          id:
+                            type: integer
+
+  - do:
+      bulk:
+        index: test
+        refresh: true
+        body:
+          - '{ "create": { } }'
+          - '{ "name": "A", "path": [ { "to": [ { "some" : [ { "id": 10 }, { "id": [1, 3, 2] } ] }, { "some": { "id": 100 } } ] }, { "to": { "some": { "id": [1000, 2000] } } } ] }'
+  - match: { errors: false }
+
+  - do:
+      search:
+        index: test
+        sort: name
+  - match:  { hits.hits.0._source.name: A }
+  - length: { hits.hits.0._source.path.to.some: 2}
+  - match: { hits.hits.0._source.path.to.some.0.id: 10 }
+  - match: { hits.hits.0._source.path.to.some.1.id: [ 1, 3, 2] }
+
+
 ---
 # 112156
 stored field under object with store_array_source:

server/src/main/java/org/elasticsearch/index/IndexSettings.java

@@ -652,8 +652,8 @@ public Iterator<Setting<?>> settings() {
     );
 
     public static final Setting<Boolean> SYNTHETIC_SOURCE_SECOND_DOC_PARSING_PASS_SETTING = Setting.boolSetting(
-        "index.synthetic_source.enable_second_doc_parsing_pass",
-        false,
+            "index.synthetic_source.enable_second_doc_parsing_pass",
+        true,
         Property.IndexScope,
         Property.Dynamic
     );