Tests: Do not index dummy documents in ExistsMissingTests.

This way we make sure that there is only one mapping for
_field_names.

src/main/java/org/elasticsearch/index/query/ExistsFilterParser.java

@@ -33,7 +33,6 @@ import org.elasticsearch.index.mapper.internal.FieldNamesFieldMapper;
 
 import java.io.IOException;
 import java.util.List;
-import java.util.Set;
 
 import static org.elasticsearch.index.query.support.QueryParsers.wrapSmartNameFilter;
 

src/test/java/org/elasticsearch/search/query/ExistsMissingTests.java

@@ -91,7 +91,10 @@ public class ExistsMissingTests extends ElasticsearchIntegrationTest {
         for (Map<String, Object> source : sources) {
             reqs.add(client().prepareIndex("idx", "type").setSource(source));
         }
-        indexRandom(true, reqs);
+        // We do NOT index dummy documents, otherwise the type for these dummy documents
+        // would have _field_names indexed while the current type might not which might
+        // confuse the exists/missing parser at query time
+        indexRandom(true, false, reqs);
 
         final Map<String, Integer> expected = new LinkedHashMap<String, Integer>();
         expected.put("foo", 1);