Ensure we don't return values for object fields.

Author: jtibshirani

server/src/main/java/org/elasticsearch/search/fetch/subphase/FetchFieldsPhase.java

@@ -53,6 +53,9 @@ public void hitExecute(SearchContext context, HitContext hitContext) {
 
         Set<String> fields = new HashSet<>();
         for (String fieldPattern : context.fetchFieldsContext().fields()) {
+            if (documentMapper.objectMappers().containsKey(fieldPattern)) {
+                continue;
+            }
             Collection<String> concreteFields = context.mapperService().simpleMatchToFullName(fieldPattern);
             fields.addAll(concreteFields);
         }

server/src/test/java/org/elasticsearch/search/fetch/subphase/FetchFieldsPhaseTests.java

@@ -157,6 +157,18 @@ public void testNonExistentFields() throws IOException {
         assertFalse(hitContext.hit().getFields().containsKey("non_existent"));
     }
 
+    public void testObjectFields() throws IOException {
+        XContentBuilder source = XContentFactory.jsonBuilder().startObject()
+            .array("field", "first", "second")
+            .startObject("object")
+                .field("field", "third")
+            .endObject()
+        .endObject();
+
+        FetchSubPhase.HitContext hitContext = hitExecute(indexService, source, "object");
+        assertFalse(hitContext.hit().getFields().containsKey("object"));
+    }
+
     private FetchSubPhase.HitContext hitExecute(IndexService indexService, XContentBuilder source, String field) {
         return hitExecute(indexService, source, List.of(field));
     }