From f00a419f81e0e1aa1b07ea69d5f1074eb4ff5511 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christoph=20B=C3=BCscher?= <cbuescher@posteo.de>
Date: Tue, 24 Sep 2019 21:00:58 +0200
Subject: [PATCH] Also handle cases where mappings stored without a type in
 template

---
 .../deprecation/ClusterDeprecationChecks.java    | 16 +++++++++-------
 .../ClusterDeprecationChecksTests.java           | 15 +++++++++++++++
 2 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/x-pack/plugin/deprecation/src/main/java/org/elasticsearch/xpack/deprecation/ClusterDeprecationChecks.java b/x-pack/plugin/deprecation/src/main/java/org/elasticsearch/xpack/deprecation/ClusterDeprecationChecks.java
index 8abdb37ba7ac1..c1948d3446b5c 100644
--- a/x-pack/plugin/deprecation/src/main/java/org/elasticsearch/xpack/deprecation/ClusterDeprecationChecks.java
+++ b/x-pack/plugin/deprecation/src/main/java/org/elasticsearch/xpack/deprecation/ClusterDeprecationChecks.java
@@ -13,7 +13,6 @@
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.common.xcontent.XContentHelper;
-import org.elasticsearch.common.xcontent.XContentType;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.mapper.FieldNamesFieldMapper;
 import org.elasticsearch.ingest.IngestService;
@@ -105,12 +104,15 @@ static DeprecationIssue checkTemplatesWithFieldNamesDisabled(ClusterState state)
         state.getMetaData().getTemplates().forEach((templateCursor) -> {
             String templateName = templateCursor.key;
             templateCursor.value.getMappings().forEach((mappingCursor) -> {
-                Map<String, Object> map = XContentHelper.convertToMap(mappingCursor.value.compressedReference(), false, XContentType.JSON)
-                        .v2();
-                // map should contain only type name at this level
-                assert map.size() == 1;
-                String type = map.keySet().iterator().next();
-                if (mapContainsFieldNamesDisabled((Map<?,?>) map.get(type))) {
+                String type = mappingCursor.key;
+                // there should be the type name at this level, but there was a bug where mappings could be stored without a type (#45120)
+                // to make sure, we try to detect this like we try to do in MappingMetaData#sourceAsMap()
+                Map<String, Object> mapping = XContentHelper.convertToMap(mappingCursor.value.compressedReference(), true).v2();
+                if (mapping.size() == 1 && mapping.containsKey(type)) {
+                    // the type name is the root value, reduce it
+                    mapping = (Map<String, Object>) mapping.get(type);
+                }
+                if (mapContainsFieldNamesDisabled(mapping)) {
                     templatesContainingFieldNames.add(templateName);
                 }
             });
diff --git a/x-pack/plugin/deprecation/src/test/java/org/elasticsearch/xpack/deprecation/ClusterDeprecationChecksTests.java b/x-pack/plugin/deprecation/src/test/java/org/elasticsearch/xpack/deprecation/ClusterDeprecationChecksTests.java
index cf19dc61b8fb9..f63a62331da70 100644
--- a/x-pack/plugin/deprecation/src/test/java/org/elasticsearch/xpack/deprecation/ClusterDeprecationChecksTests.java
+++ b/x-pack/plugin/deprecation/src/test/java/org/elasticsearch/xpack/deprecation/ClusterDeprecationChecksTests.java
@@ -192,6 +192,21 @@ public void testTemplatesWithFieldNamesDisabled() throws IOException {
         }
         badMappingBuilder.endObject();
         assertFieldNamesEnabledTemplate(badMappingBuilder, true);
+
+        // however, there was a bug where mappings could be stored without a type (#45120)
+        // so we also should try to check these cases
+
+        XContentBuilder badMappingWithoutTypeBuilder = jsonBuilder();
+        badMappingWithoutTypeBuilder.startObject();
+        {
+            badMappingWithoutTypeBuilder.startObject(FieldNamesFieldMapper.NAME);
+            {
+                badMappingWithoutTypeBuilder.field("enabled", randomBoolean());
+            }
+            badMappingWithoutTypeBuilder.endObject();
+        }
+        badMappingWithoutTypeBuilder.endObject();
+        assertFieldNamesEnabledTemplate(badMappingWithoutTypeBuilder, true);
     }
 
     private void assertFieldNamesEnabledTemplate(XContentBuilder templateBuilder, boolean expectIssue) throws IOException {