From 543075b84568ffd3b664d86843d3de9098caf448 Mon Sep 17 00:00:00 2001
From: Mingliang Liu <liuml07@apache.org>
Date: Mon, 8 Jun 2020 10:11:30 -0700
Subject: [PATCH] HADOOP-17059. ArrayIndexOfboundsException in
 ViewFileSystem#listStatus. Contributed by hemanthboyina

---
 .../hadoop/fs/viewfs/ViewFileSystem.java      |  2 +-
 .../hadoop/fs/viewfs/ViewFsBaseTest.java      | 22 +++++++++++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFileSystem.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFileSystem.java
index 115fc033f2..0acb04d33d 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFileSystem.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFileSystem.java
@@ -1221,7 +1221,7 @@ public FileStatus[] listStatus(Path f) throws AccessControlException,
         } else {
           result[i++] = new FileStatus(0, true, 0, 0,
             creationTime, creationTime, PERMISSION_555,
-            ugi.getShortUserName(), ugi.getGroupNames()[0],
+            ugi.getShortUserName(), ugi.getPrimaryGroupName(),
             new Path(inode.fullPath).makeQualified(
                 myUri, null));
         }
diff --git a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/ViewFsBaseTest.java b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/ViewFsBaseTest.java
index d96cdb172b..90722aab2f 100644
--- a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/ViewFsBaseTest.java
+++ b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/ViewFsBaseTest.java
@@ -56,6 +56,7 @@
 import org.apache.hadoop.fs.RemoteIterator;
 import org.apache.hadoop.fs.FileContextTestHelper.fileType;
 import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.FsConstants;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.fs.UnresolvedLinkException;
@@ -69,6 +70,7 @@
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.security.token.Token;
 import org.apache.hadoop.test.GenericTestUtils;
+import org.apache.hadoop.test.LambdaTestUtils;
 import org.junit.After;
 import org.junit.Assert;
 import org.junit.Before;
@@ -1001,4 +1003,24 @@ static AbstractFileSystem getMockFs(URI uri) {
       return mockFs;
     }
   }
+
+  @Test
+  public void testListStatusWithNoGroups() throws Exception {
+    final UserGroupInformation userUgi = UserGroupInformation
+        .createUserForTesting("user@HADOOP.COM", new String[] {});
+    userUgi.doAs(new PrivilegedExceptionAction<Object>() {
+      @Override
+      public Object run() throws Exception {
+        String clusterName = Constants.CONFIG_VIEWFS_DEFAULT_MOUNT_TABLE;
+        URI viewFsUri =
+            new URI(FsConstants.VIEWFS_SCHEME, clusterName, "/", null, null);
+        FileSystem vfs = FileSystem.get(viewFsUri, conf);
+        LambdaTestUtils.intercept(IOException.class,
+            "There is no primary group for UGI", () -> vfs
+                .listStatus(new Path(viewFsUri.toString() + "internalDir")));
+        return null;
+      }
+    });
+  }
+
 }