Fix directory listing with leading slash

google-cloud-contrib/google-cloud-nio/src/main/java/com/google/cloud/storage/contrib/nio/CloudStorageFileSystemProvider.java

@@ -598,7 +598,7 @@ public DirectoryStream<Path> newDirectoryStream(Path dir, final Filter<? super P
     final CloudStoragePath cloudPath = CloudStorageUtil.checkPath(dir);
     checkNotNull(filter);
     initStorage();
-    String prefix = cloudPath.toString();
+    String prefix = cloudPath.toRealPath().toString();
     final Iterator<Blob> blobIterator = storage.list(cloudPath.bucket(),
         Storage.BlobListOption.prefix(prefix), Storage.BlobListOption.currentDirectory(),
         Storage.BlobListOption.fields()).iterateAll();

google-cloud-contrib/google-cloud-nio/src/test/java/com/google/cloud/storage/contrib/nio/CloudStorageFileSystemTest.java

@@ -158,6 +158,13 @@ public void testListFiles() throws IOException {
         got.add(path);
       }
       assertThat(got).containsExactlyElementsIn(goodPaths);
+
+      // Must also work with relative path
+      got.clear();
+      for (Path path : Files.newDirectoryStream(fs.getPath("dir/"))) {
+        got.add(path);
+      }
+      assertThat(got).containsExactlyElementsIn(goodPaths);
     }
   }
 

google-cloud-contrib/google-cloud-nio/src/test/java/com/google/cloud/storage/contrib/nio/it/ITGcsNio.java

@@ -347,6 +347,13 @@ public void testListFiles() throws IOException {
       }
 
       List<Path> got = new ArrayList<>();
+      for (Path path : Files.newDirectoryStream(fs.getPath("/dir/"))) {
+        got.add(path);
+      }
+      assertThat(got).containsExactlyElementsIn(goodPaths);
+
+      // Must also work with relative path
+      got.clear();
       for (Path path : Files.newDirectoryStream(fs.getPath("dir/"))) {
         got.add(path);
       }