--- a/src/java.base/share/classes/jdk/internal/jrtfs/JrtFileSystem.java	Thu Dec 13 16:14:07 2018 +0100
+++ b/src/java.base/share/classes/jdk/internal/jrtfs/JrtFileSystem.java	Thu Dec 13 15:31:05 2018 +0100
@@ -123,7 +123,7 @@
         StringBuilder sb = new StringBuilder();
         sb.append(first);
         for (String path : more) {
-            if (path.length() > 0) {
+            if (!path.isEmpty()) {
                 if (sb.length() > 0) {
                     sb.append('/');
                 }