wildcard query on _index (#27334)

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

@@ -27,6 +27,7 @@ import org.apache.lucene.util.BytesRef;
 import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.lucene.Lucene;
 import org.elasticsearch.common.lucene.search.Queries;
+import org.elasticsearch.common.regex.Regex;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.index.fielddata.IndexFieldData;
@@ -150,12 +151,8 @@ public class IndexFieldMapper extends MetadataFieldMapper {
         }
 
         private boolean isSameIndex(Object value, String indexName) {
-            if (value instanceof BytesRef) {
-                BytesRef indexNameRef = new BytesRef(indexName);
-                return (indexNameRef.bytesEquals((BytesRef) value));
-            } else {
-                return indexName.equals(value.toString());
-            }
+            String pattern = value instanceof BytesRef ? pattern = ((BytesRef) value).utf8ToString() : value.toString();
+            return Regex.simpleMatch(pattern, indexName);
         }
 
         @Override

core/src/main/java/org/elasticsearch/index/query/WildcardQueryBuilder.java

@@ -20,6 +20,8 @@
 package org.elasticsearch.index.query;
 
 import org.apache.lucene.index.Term;
+import org.apache.lucene.search.MatchAllDocsQuery;
+import org.apache.lucene.search.MatchNoDocsQuery;
 import org.apache.lucene.search.MultiTermQuery;
 import org.apache.lucene.search.Query;
 import org.apache.lucene.search.WildcardQuery;
@@ -31,6 +33,7 @@ import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.lucene.BytesRefs;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
+import org.elasticsearch.index.mapper.IndexFieldMapper;
 import org.elasticsearch.index.mapper.MappedFieldType;
 import org.elasticsearch.index.query.support.QueryParsers;
 
@@ -187,6 +190,9 @@ public class WildcardQueryBuilder extends AbstractQueryBuilder<WildcardQueryBuil
             term = new Term(fieldName, BytesRefs.toBytesRef(value));
         } else {
             Query termQuery = fieldType.termQuery(value, context);
+            if (termQuery instanceof MatchNoDocsQuery || termQuery instanceof MatchAllDocsQuery) {
+                return termQuery;
+            }
             term = MappedFieldType.extractTerm(termQuery);
         }
 

core/src/test/java/org/elasticsearch/index/query/WildcardQueryBuilderTests.java

@@ -20,6 +20,8 @@
 package org.elasticsearch.index.query;
 
 import org.apache.lucene.index.Term;
+import org.apache.lucene.search.MatchAllDocsQuery;
+import org.apache.lucene.search.MatchNoDocsQuery;
 import org.apache.lucene.search.Query;
 import org.apache.lucene.search.WildcardQuery;
 import org.elasticsearch.common.ParsingException;
@@ -136,4 +138,20 @@ public class WildcardQueryBuilderTests extends AbstractQueryTestCase<WildcardQue
             assertEquals(expected, query);
         }
     }
+    
+    public void testIndexWildcard() throws IOException {
+        assumeTrue("test runs only when at least a type is registered", getCurrentTypes().length > 0);
+
+        QueryShardContext context = createShardContext();
+        String index = context.getFullyQualifiedIndexName();
+        
+        Query query = new WildcardQueryBuilder("_index", index).doToQuery(context);
+        assertThat(query instanceof MatchAllDocsQuery, equalTo(true));
+        
+        query = new WildcardQueryBuilder("_index", index + "*").doToQuery(context);
+        assertThat(query instanceof MatchAllDocsQuery, equalTo(true));
+        
+        query = new WildcardQueryBuilder("_index", "index_" + index + "*").doToQuery(context);
+        assertThat(query instanceof MatchNoDocsQuery, equalTo(true));
+    }
 }