Ensure nested documents have consistent version and seq_ids

core/src/main/java/org/elasticsearch/index/mapper/SeqNoFieldMapper.java

@@ -245,15 +245,18 @@ public Mapper parse(ParseContext context) throws IOException {
 
     @Override
     public void postParse(ParseContext context) throws IOException {
-        // In the case of nested docs, let's fill nested docs with seqNo=1 and
-        // primaryTerm=0 so that Lucene doesn't write a Bitset for documents
-        // that don't have the field. This is consistent with the default value
+        // In the case of nested docs, let's fill nested docs with the original
+        // so that Lucene doesn't write a Bitset for documents that
+        // don't have the field. This is consistent with the default value
         // for efficiency.
+        // we share the parent docs fields to ensure good compression
+        SequenceIDFields seqID = context.seqID();
+        assert seqID != null;
         for (int i = 1; i < context.docs().size(); i++) {
             final Document doc = context.docs().get(i);
-            doc.add(new LongPoint(NAME, 1));
-            doc.add(new NumericDocValuesField(NAME, 1L));
-            doc.add(new NumericDocValuesField(PRIMARY_TERM_NAME, 0L));
+            doc.add(seqID.seqNo);
+            doc.add(seqID.seqNoDocValue);
+            doc.add(seqID.primaryTerm);
         }
     }
 

core/src/main/java/org/elasticsearch/index/mapper/VersionFieldMapper.java

@@ -126,9 +126,11 @@ public Mapper parse(ParseContext context) throws IOException {
     public void postParse(ParseContext context) throws IOException {
         // In the case of nested docs, let's fill nested docs with version=1 so that Lucene doesn't write a Bitset for documents
         // that don't have the field. This is consistent with the default value for efficiency.
+        Field version = context.version();
+        assert version != null;
         for (int i = 1; i < context.docs().size(); i++) {
             final Document doc = context.docs().get(i);
-            doc.add(new NumericDocValuesField(NAME, 1L));
+            doc.add(version);
         }
     }
 

rest-api-spec/src/main/resources/rest-api-spec/test/search.inner_hits/10_basic.yml

@@ -41,3 +41,60 @@ setup:
     - match: { hits.hits.0.inner_hits.nested_field.hits.hits.0._nested.offset: 0 }
     - is_false: hits.hits.0.inner_hits.nested_field.hits.hits.0._nested.child
 
+
+---
+"Nested doc version and seqIDs":
+
+    - skip:
+        # fixed in 7.0
+        version: " - 6.99.99"
+        reason:  "version and seq IDs where not accurate in previous versions"
+
+    - do:
+        index:
+          index: test
+          type:  type_1
+          id:    1
+          body:
+            "nested_field" : [ { "foo": "bar" } ]
+    - do:
+        indices.refresh: {}
+
+    - do:
+        search:
+          body: { "query" : { "nested" : { "path" : "nested_field", "query" : { "match_all" : {} }, "inner_hits" : { version: true, "docvalue_fields": ["_seq_no"]} }}, "version": true, "docvalue_fields" : ["_seq_no"] }
+
+    - match: { hits.total: 1 }
+    - match: { hits.hits.0._index: "test" }
+    - match: { hits.hits.0._type: "type_1" }
+    - match: { hits.hits.0._id: "1" }
+    - match: { hits.hits.0._version: 1 }
+    - match: { hits.hits.0.fields._seq_no: [0] }
+    - match: { hits.hits.0.inner_hits.nested_field.hits.hits.0.fields._seq_no: [0] }
+
+
+    - do:
+        index:
+          index: test
+          type:  type_1
+          id:    1
+          body:
+            "nested_field" : [ { "foo": "baz" } ]
+    - do:
+        indices.refresh: {}
+
+    - do:
+        search:
+          body: { "query" : { "nested" : { "path" : "nested_field", "query" : { "match_all" : {} }, "inner_hits" : { version: true, "docvalue_fields": ["_seq_no"]} }}, "version": true, "docvalue_fields" : ["_seq_no"] }
+
+    - match: { hits.total: 1 }
+    - match: { hits.hits.0._index: "test" }
+    - match: { hits.hits.0._type: "type_1" }
+    - match: { hits.hits.0._id: "1" }
+    - match: { hits.hits.0._version: 2 }
+    - match: { hits.hits.0.fields._seq_no: [1] }
+    - match: { hits.hits.0.inner_hits.nested_field.hits.hits.0._version: 2 }
+    - match: { hits.hits.0.inner_hits.nested_field.hits.hits.0.fields._seq_no: [1] }
+
+
+