From 59742ee0a441ad26b2e13be40afa04b06e4ec978 Mon Sep 17 00:00:00 2001
From: Adrien Grand <jpountz@gmail.com>
Date: Fri, 15 Jan 2016 16:54:07 +0100
Subject: [PATCH] Reuse metadata mappers for dynamic updates.

When a metadata mapper is not specified in a mapping update, it should default
to the current metadata mapper instead of the general default in order for the
update to not conflict with the current mapping.

Closes #15997
---
 .../index/mapper/DocumentMapper.java          | 14 +++++++++--
 .../mapper/merge/TestMergeMapperTests.java    | 25 +++++++++++++++++++
 2 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/core/src/main/java/org/elasticsearch/index/mapper/DocumentMapper.java b/core/src/main/java/org/elasticsearch/index/mapper/DocumentMapper.java
index c2d644d393d..0528541238a 100644
--- a/core/src/main/java/org/elasticsearch/index/mapper/DocumentMapper.java
+++ b/core/src/main/java/org/elasticsearch/index/mapper/DocumentMapper.java
@@ -79,10 +79,20 @@ public class DocumentMapper implements ToXContent {
             this.builderContext = new Mapper.BuilderContext(indexSettings, new ContentPath(1));
             this.rootObjectMapper = builder.build(builderContext);
 
+            final String type = rootObjectMapper.name();
+            DocumentMapper existingMapper = mapperService.documentMapper(type);
             for (Map.Entry<String, MetadataFieldMapper.TypeParser> entry : mapperService.mapperRegistry.getMetadataMapperParsers().entrySet()) {
                 final String name = entry.getKey();
-                final TypeParser parser = entry.getValue();
-                final MetadataFieldMapper metadataMapper = parser.getDefault(indexSettings, mapperService.fullName(name), builder.name());
+                final MetadataFieldMapper existingMetadataMapper = existingMapper == null
+                        ? null
+                        : (MetadataFieldMapper) existingMapper.mappers().getMapper(name);
+                final MetadataFieldMapper metadataMapper;
+                if (existingMetadataMapper == null) {
+                    final TypeParser parser = entry.getValue();
+                    metadataMapper = parser.getDefault(indexSettings, mapperService.fullName(name), builder.name());
+                } else {
+                    metadataMapper = existingMetadataMapper;
+                }
                 metadataMappers.put(metadataMapper.getClass(), metadataMapper);
             }
         }
diff --git a/core/src/test/java/org/elasticsearch/index/mapper/merge/TestMergeMapperTests.java b/core/src/test/java/org/elasticsearch/index/mapper/merge/TestMergeMapperTests.java
index 80f7942bbcc..1600205238a 100644
--- a/core/src/test/java/org/elasticsearch/index/mapper/merge/TestMergeMapperTests.java
+++ b/core/src/test/java/org/elasticsearch/index/mapper/merge/TestMergeMapperTests.java
@@ -34,6 +34,7 @@ import org.elasticsearch.index.mapper.core.StringFieldMapper;
 import org.elasticsearch.index.mapper.object.ObjectMapper;
 import org.elasticsearch.test.ESSingleNodeTestCase;
 
+import java.io.IOException;
 import java.util.concurrent.CyclicBarrier;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicReference;
@@ -203,4 +204,28 @@ public class TestMergeMapperTests extends ESSingleNodeTestCase {
             throw error.get();
         }
     }
+
+    public void testDoNotRepeatOriginalMapping() throws IOException {
+        CompressedXContent mapping = new CompressedXContent(XContentFactory.jsonBuilder().startObject()
+                .startObject("type")
+                    .startObject("_source")
+                        .field("enabled", false)
+                    .endObject()
+                .endObject().endObject().bytes());
+        MapperService mapperService = createIndex("test").mapperService();
+        mapperService.merge("type", mapping, true, false);
+
+        CompressedXContent update = new CompressedXContent(XContentFactory.jsonBuilder().startObject()
+                .startObject("type")
+                    .startObject("properties")
+                        .startObject("foo")
+                            .field("type", "string")
+                        .endObject()
+                    .endObject()
+                .endObject().endObject().bytes());
+        DocumentMapper mapper = mapperService.merge("type", update, false, false);
+
+        assertNotNull(mapper.mappers().getMapper("foo"));
+        assertFalse(mapper.sourceMapper().enabled());
+    }
 }