Give precedence to index creation when mixing typed templates with typeless index creation and vice-versa.

rest-api-spec/src/main/resources/rest-api-spec/test/indices.create/20_mix_typeless_typeful.yml

@@ -0,0 +1,77 @@
+---
+"Create a typeless index while there is a typed template":
+
+ - skip:
+      version: " - 6.99.99"
+      reason: needs change to be backported to 6.7
+
+ - do:
+      indices.put_template:
+          include_type_name: true
+          name: test_template
+          body:
+              index_patterns: test-*
+              mappings:
+                  my_type:
+                      properties:
+                          foo:
+                              type: keyword
+
+ - do:
+      indices.create:
+          include_type_name: false
+          index: test-1
+          body:
+              mappings:
+                  properties:
+                      bar:
+                          type: "long"
+
+ - do:
+      indices.get_mapping:
+          include_type_name: true
+          index: test-1
+
+ - is_true: test-1.mappings._doc # the index creation call won
+ - is_false: test-1.mappings.my_type
+ - is_true: test-1.mappings._doc.properties.foo
+ - is_true: test-1.mappings._doc.properties.bar
+
+---
+"Create a typed index while there is a typeless template":
+
+ - skip:
+      version: " - 6.99.99"
+      reason: needs change to be backported to 6.7
+
+ - do:
+      indices.put_template:
+          include_type_name: false
+          name: test_template
+          body:
+              index_patterns: test-*
+              mappings:
+                  properties:
+                      foo:
+                          type: keyword
+
+ - do:
+      indices.create: 
+          include_type_name: true
+          index: test-1
+          body:
+              mappings:
+                  my_type:
+                      properties:
+                          bar:
+                              type: "long"
+
+ - do:
+      indices.get_mapping:
+          include_type_name: true
+          index: test-1
+
+ - is_true: test-1.mappings.my_type # the index creation call won
+ - is_false: test-1.mappings._doc
+ - is_true: test-1.mappings.my_type.properties.foo
+ - is_true: test-1.mappings.my_type.properties.bar

server/src/main/java/org/elasticsearch/cluster/metadata/MetaDataCreateIndexService.java

@@ -318,6 +318,28 @@ public ClusterState execute(ClusterState currentState) throws Exception {
                             if (mappings.containsKey(cursor.key)) {
                                 XContentHelper.mergeDefaults(mappings.get(cursor.key),
                                     MapperService.parseMapping(xContentRegistry, mappingString));
+                            } else if (mappings.size() == 1 && cursor.key.equals(MapperService.SINGLE_MAPPING_NAME)) {
+                                // Typeless template with typed mapping
+                                Map<String, Object> templateMapping = MapperService.parseMapping(xContentRegistry, mappingString);
+                                assert templateMapping.size() == 1 : templateMapping;
+                                assert cursor.key.equals(templateMapping.keySet().iterator().next()) :
+                                    cursor.key + " != " + templateMapping;
+                                Map.Entry<String, Map<String, Object>> mappingEntry = mappings.entrySet().iterator().next();
+                                templateMapping = Collections.singletonMap(
+                                        mappingEntry.getKey(),                       // reuse type name from the mapping
+                                        templateMapping.values().iterator().next()); // but actual mappings from the template
+                                XContentHelper.mergeDefaults(mappingEntry.getValue(), templateMapping);
+                            } else if (template.mappings().size() == 1 && mappings.containsKey(MapperService.SINGLE_MAPPING_NAME)) {
+                                // Typed template with typeless mapping
+                                Map<String, Object> templateMapping = MapperService.parseMapping(xContentRegistry, mappingString);
+                                assert templateMapping.size() == 1 : templateMapping;
+                                assert cursor.key.equals(templateMapping.keySet().iterator().next()) :
+                                    cursor.key + " != " + templateMapping;
+                                Map<String, Object> mapping = mappings.get(MapperService.SINGLE_MAPPING_NAME);
+                                templateMapping = Collections.singletonMap(
+                                        MapperService.SINGLE_MAPPING_NAME,           // make template mapping typeless
+                                        templateMapping.values().iterator().next());
+                                XContentHelper.mergeDefaults(mapping, templateMapping);
                             } else {
                                 mappings.put(cursor.key,
                                     MapperService.parseMapping(xContentRegistry, mappingString));