Mapper plugin overwrite date mapping

If you define some specific mapping for your file content, such as the following:

```javascript
{
    "person": {
        "properties": {
            "file": {
                "type": "attachment",
                "path": "full",
                "fields": {
                    "date": { "type": "string" }
                }
            }
        }
    }
}
```

And then, if you ask back the mapping, you get:

```javascript
{
   "person":{
      "properties":{
         "file":{
            "type":"attachment",
            "path":"full",
            "fields":{
               "file":{
                  "type":"string"
               },
               "author":{
                  "type":"string"
               },
               "title":{
                  "type":"string"
               },
               "name":{
                  "type":"string"
               },
               "date":{
                  "type":"date",
                  "format":"dateOptionalTime"
               },
               "keywords":{
                  "type":"string"
               },
               "content_type":{
                  "type":"string"
               }
            }
         }
      }
   }
}
```

All your settings have been overwrited by the mapper plugin.

See also issue #22 where the issue was found.

Closes #39.

src/main/java/org/elasticsearch/index/mapper/attachment/AttachmentMapper.java

@@ -223,18 +223,23 @@ public class AttachmentMapper implements Mapper {
 
                         // Check if we have a multifield here
                         boolean isMultifield = false;
+                        boolean isString = false;
                         if (propNode != null && propNode instanceof Map) {
                             Object oType = ((Map<String, Object>) propNode).get("type");
                             if (oType != null && oType.equals(MultiFieldMapper.CONTENT_TYPE)) {
                                 isMultifield = true;
                             }
+                            if (oType != null && oType.equals(StringFieldMapper.CONTENT_TYPE)) {
+                                isString = true;
+                            }
                         }
 
                         if (name.equals(propName)) {
                             // that is the content
                             builder.content(parserContext.typeParser(isMultifield? MultiFieldMapper.CONTENT_TYPE:StringFieldMapper.CONTENT_TYPE).parse(name, (Map<String, Object>) propNode, parserContext));
                         } else if ("date".equals(propName)) {
-                            builder.date(parserContext.typeParser(isMultifield? MultiFieldMapper.CONTENT_TYPE:DateFieldMapper.CONTENT_TYPE).parse("date", (Map<String, Object>) propNode, parserContext));
+                            // If a specific format is already defined here, we should use it
+                            builder.date(parserContext.typeParser(isMultifield ? MultiFieldMapper.CONTENT_TYPE : isString ? StringFieldMapper.CONTENT_TYPE : DateFieldMapper.CONTENT_TYPE).parse("date", (Map<String, Object>) propNode, parserContext));
                         } else if ("title".equals(propName)) {
                             builder.title(parserContext.typeParser(isMultifield? MultiFieldMapper.CONTENT_TYPE:StringFieldMapper.CONTENT_TYPE).parse("title", (Map<String, Object>) propNode, parserContext));
                         } else if ("name".equals(propName)) {

src/test/java/org/elasticsearch/index/mapper/xcontent/DateAttachmentMapperTests.java

@@ -0,0 +1,57 @@
+/*
+ * Licensed to ElasticSearch and Shay Banon under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. ElasticSearch licenses this
+ * file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.index.mapper.xcontent;
+
+import org.elasticsearch.index.Index;
+import org.elasticsearch.index.analysis.AnalysisService;
+import org.elasticsearch.index.mapper.DocumentMapper;
+import org.elasticsearch.index.mapper.DocumentMapperParser;
+import org.elasticsearch.index.mapper.attachment.AttachmentMapper;
+import org.elasticsearch.index.mapper.core.StringFieldMapper;
+import org.testng.annotations.BeforeClass;
+import org.testng.annotations.Test;
+
+import static org.elasticsearch.common.io.Streams.copyToStringFromClasspath;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.instanceOf;
+
+/**
+ *
+ */
+@Test
+public class DateAttachmentMapperTests {
+
+    private DocumentMapperParser mapperParser;
+
+    @BeforeClass
+    public void setupMapperParser() {
+        mapperParser = new DocumentMapperParser(new Index("test"), new AnalysisService(new Index("test")), null, null);
+        mapperParser.putTypeParser(AttachmentMapper.CONTENT_TYPE, new AttachmentMapper.TypeParser());
+    }
+
+    @Test
+    public void testSimpleMappings() throws Exception {
+        String mapping = copyToStringFromClasspath("/org/elasticsearch/index/mapper/date/date-mapping.json");
+        DocumentMapper docMapper = mapperParser.parse(mapping);
+
+        // Our mapping should be kept as a String
+        assertThat(docMapper.mappers().fullName("file.date").mapper(), instanceOf(StringFieldMapper.class));
+    }
+}

src/test/resources/org/elasticsearch/index/mapper/date/date-mapping.json

@@ -0,0 +1,13 @@
+{
+    "person": {
+        "properties": {
+            "file": {
+                "type": "attachment",
+                "path": "full",
+                "fields": {
+                    "date": { "type": "string" }
+                }
+            }
+        }
+    }
+}