add a check to not allow to create an alias with a name of an existing index

modules/elasticsearch/src/main/java/org/elasticsearch/cluster/metadata/MetaDataIndexAliasesService.java

@@ -27,6 +27,7 @@ import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.index.Index;
 import org.elasticsearch.indices.IndexMissingException;
+import org.elasticsearch.indices.InvalidAliasNameException;
 
 import java.util.Set;
 
@@ -57,6 +58,10 @@ public class MetaDataIndexAliasesService extends AbstractComponent {
                         listener.onFailure(new IndexMissingException(new Index(aliasAction.index())));
                         return currentState;
                     }
+                    if (currentState.metaData().hasIndex(aliasAction.alias())) {
+                        listener.onFailure(new InvalidAliasNameException(new Index(aliasAction.index()), aliasAction.alias(), "an index exists with the same name as the alias"));
+                        return currentState;
+                    }
                 }
 
                 MetaData.Builder builder = newMetaDataBuilder().metaData(currentState.metaData());

modules/elasticsearch/src/main/java/org/elasticsearch/cluster/metadata/MetaDataMappingService.java

@@ -31,12 +31,12 @@ import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.index.Index;
 import org.elasticsearch.index.mapper.DocumentMapper;
-import org.elasticsearch.index.mapper.InvalidTypeNameException;
 import org.elasticsearch.index.mapper.MapperService;
 import org.elasticsearch.index.mapper.MergeMappingException;
 import org.elasticsearch.index.service.IndexService;
 import org.elasticsearch.indices.IndexMissingException;
 import org.elasticsearch.indices.IndicesService;
+import org.elasticsearch.indices.InvalidTypeNameException;
 
 import java.io.IOException;
 import java.util.Map;

modules/elasticsearch/src/main/java/org/elasticsearch/index/mapper/MapperService.java

@@ -40,6 +40,7 @@ import org.elasticsearch.index.Index;
 import org.elasticsearch.index.analysis.AnalysisService;
 import org.elasticsearch.index.mapper.xcontent.XContentDocumentMapperParser;
 import org.elasticsearch.index.settings.IndexSettings;
+import org.elasticsearch.indices.InvalidTypeNameException;
 
 import javax.annotation.Nullable;
 import java.io.File;

modules/elasticsearch/src/main/java/org/elasticsearch/indices/InvalidAliasNameException.java

@@ -0,0 +1,33 @@
+/*
+ * Licensed to Elastic Search and Shay Banon under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. Elastic Search 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.indices;
+
+import org.elasticsearch.index.Index;
+import org.elasticsearch.index.IndexException;
+
+/**
+ * @author kimchy (shay.banon)
+ */
+public class InvalidAliasNameException extends IndexException {
+
+    public InvalidAliasNameException(Index index, String name, String desc) {
+        super(index, "Invalid alias name [" + name + "], " + desc);
+    }
+}

modules/elasticsearch/src/main/java/org/elasticsearch/indices/InvalidTypeNameException.java

@@ -17,7 +17,9 @@
  * under the License.
  */
 
-package org.elasticsearch.index.mapper;
+package org.elasticsearch.indices;
+
+import org.elasticsearch.index.mapper.MapperException;
 
 /**
  * @author kimchy (Shay Banon)

modules/elasticsearch/src/main/java/org/elasticsearch/rest/action/admin/indices/mapping/delete/RestDeleteMappingAction.java

@@ -26,9 +26,9 @@ import org.elasticsearch.client.Client;
 import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.XContentBuilder;
-import org.elasticsearch.index.mapper.InvalidTypeNameException;
 import org.elasticsearch.index.mapper.MergeMappingException;
 import org.elasticsearch.indices.IndexMissingException;
+import org.elasticsearch.indices.InvalidTypeNameException;
 import org.elasticsearch.rest.*;
 import org.elasticsearch.rest.action.support.RestXContentBuilder;
 

modules/elasticsearch/src/main/java/org/elasticsearch/rest/action/admin/indices/mapping/put/RestPutMappingAction.java

@@ -26,9 +26,9 @@ import org.elasticsearch.client.Client;
 import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.XContentBuilder;
-import org.elasticsearch.index.mapper.InvalidTypeNameException;
 import org.elasticsearch.index.mapper.MergeMappingException;
 import org.elasticsearch.indices.IndexMissingException;
+import org.elasticsearch.indices.InvalidTypeNameException;
 import org.elasticsearch.rest.*;
 import org.elasticsearch.rest.action.support.RestXContentBuilder;