Process dynamic templates in order. #18638

When calling `findTemplateBuilder(context, currentFieldName, "text", null)`,
elasticsearch ignores all templates that have a `match_mapping_type` set since
no dynamic type is provided (the last parameter, which is null in that case).
So this should only be called _last_. Otherwise, if a path-based template
matches, it will have precedence over all type-based templates.

Closes #18625

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

@@ -676,16 +676,6 @@ final class DocumentParser {
 
     private static Mapper.Builder<?,?> createBuilderFromDynamicValue(final ParseContext context, XContentParser.Token token, String currentFieldName) throws IOException {
         if (token == XContentParser.Token.VALUE_STRING) {
-            // do a quick test to see if its fits a dynamic template, if so, use it.
-            // we need to do it here so we can handle things like attachment templates, where calling
-            // text (to see if its a date) causes the binary value to be cleared
-            {
-                Mapper.Builder builder = context.root().findTemplateBuilder(context, currentFieldName, "text", null);
-                if (builder != null) {
-                    return builder;
-                }
-            }
-
             if (context.root().dateDetection()) {
                 String text = context.parser().text();
                 // a safe check since "1" gets parsed as well

core/src/main/java/org/elasticsearch/index/mapper/object/RootObjectMapper.java

@@ -278,7 +278,7 @@ public class RootObjectMapper extends ObjectMapper {
         return typeParser.parse(name, dynamicTemplate.mappingForName(name, dynamicType), parserContext);
     }
 
-    public DynamicTemplate findTemplate(ContentPath path, String name, String matchType) {
+    private DynamicTemplate findTemplate(ContentPath path, String name, String matchType) {
         for (DynamicTemplate dynamicTemplate : dynamicTemplates) {
             if (dynamicTemplate.match(path, name, matchType)) {
                 return dynamicTemplate;

core/src/test/java/org/elasticsearch/index/mapper/DynamicMappingTests.java

@@ -34,6 +34,7 @@ import org.elasticsearch.index.IndexService;
 import org.elasticsearch.index.mapper.core.BooleanFieldMapper;
 import org.elasticsearch.index.mapper.core.BooleanFieldMapper.BooleanFieldType;
 import org.elasticsearch.index.mapper.core.DateFieldMapper;
+import org.elasticsearch.index.mapper.core.KeywordFieldMapper;
 import org.elasticsearch.index.mapper.core.DateFieldMapper.DateFieldType;
 import org.elasticsearch.index.mapper.core.NumberFieldMapper;
 import org.elasticsearch.index.mapper.core.NumberFieldMapper.NumberFieldType;
@@ -645,4 +646,32 @@ public class DynamicMappingTests extends ESSingleNodeTestCase {
         mapper = defaultMapper.mappers().smartNameFieldMapper("s_double");
         assertThat(mapper, instanceOf(TextFieldMapper.class));
     }
+
+    public void testDynamicTemplateOrder() throws IOException {
+        // https://github.com/elastic/elasticsearch/issues/18625
+        // elasticsearch used to apply templates that do not have a match_mapping_type first
+        XContentBuilder mapping = XContentFactory.jsonBuilder().startObject().startObject("type")
+                .startArray("dynamic_templates")
+                    .startObject()
+                        .startObject("type-based")
+                            .field("match_mapping_type", "string")
+                            .startObject("mapping")
+                                .field("type", "keyword")
+                            .endObject()
+                        .endObject()
+                    .endObject()
+                    .startObject()
+                    .startObject("path-based")
+                        .field("path_match", "foo")
+                        .startObject("mapping")
+                            .field("type", "long")
+                        .endObject()
+                    .endObject()
+                .endObject()
+                .endArray()
+                .endObject().endObject();
+        IndexService index = createIndex("test", Settings.EMPTY, "type", mapping);
+        client().prepareIndex("test", "type", "1").setSource("foo", "abc").get();
+        assertThat(index.mapperService().fullName("foo"), instanceOf(KeywordFieldMapper.KeywordFieldType.class));
+    }
 }