paths is now the empty space by default

core/src/main/java/org/elasticsearch/cluster/metadata/MetaDataCreateIndexService.java

@@ -470,7 +470,7 @@ public class MetaDataCreateIndexService extends AbstractComponent {
         List<String> validationErrors = new ArrayList<>();
         if (Strings.isEmpty(customPath) == false && env.sharedDataFile() == null) {
             validationErrors.add("path.shared_data must be set in order to use custom data paths");
-        } else if (customPath != null) {
+        } else if (Strings.isEmpty(customPath) == false) {
             Path resolvedPath = PathUtils.get(new Path[]{env.sharedDataFile()}, customPath);
             if (resolvedPath == null) {
                 validationErrors.add("custom path [" + customPath + "] is not a sub-path of path.shared_data [" + env.sharedDataFile() + "]");

core/src/test/java/org/elasticsearch/action/admin/indices/template/put/MetaDataIndexTemplateServiceTests.java

@@ -105,7 +105,6 @@ public class MetaDataIndexTemplateServiceTests extends ESTestCase {
 
             @Override
             public void onFailure(Throwable t) {
-                t.printStackTrace();
                 throwables.add(t);
             }
         });