HDFS-9852. hdfs dfs -setfacl error message is misleading (Wei-Chiu Chuang via aw)

(cherry picked from commit b3649adf6a1b2dc47566b4b0d652bd4e0a6a8056)
(cherry picked from commit 84c785036f5014d4e6066b344c2c235d1ea5028f)

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/shell/AclCommands.java

@@ -192,6 +192,9 @@ class AclCommands extends FsCommand {
       boolean oneRemoveOption = cf.getOpt("b") || cf.getOpt("k");
       boolean oneModifyOption = cf.getOpt("m") || cf.getOpt("x");
       boolean setOption = cf.getOpt("-set");
+      boolean hasExpectedOptions = cf.getOpt("b") || cf.getOpt("k") ||
+          cf.getOpt("m") || cf.getOpt("x") || cf.getOpt("-set");
+
       if ((bothRemoveOptions || bothModifyOptions)
           || (oneRemoveOption && oneModifyOption)
           || (setOption && (oneRemoveOption || oneModifyOption))) {
@@ -201,8 +204,13 @@ class AclCommands extends FsCommand {
 
       // Only -m, -x and --set expects <acl_spec>
       if (oneModifyOption || setOption) {
+        if (args.isEmpty()) {
+          throw new HadoopIllegalArgumentException(
+              "Missing arguments: <acl_spec> <path>");
+        }
         if (args.size() < 2) {
-          throw new HadoopIllegalArgumentException("<acl_spec> is missing");
+          throw new HadoopIllegalArgumentException(
+              "Missing either <acl_spec> or <path>");
         }
         aclEntries = AclEntry.parseAclSpec(args.removeFirst(), !cf.getOpt("x"));
       }
@@ -214,6 +222,10 @@ class AclCommands extends FsCommand {
         throw new HadoopIllegalArgumentException("Too many arguments");
       }
 
+      if (!hasExpectedOptions) {
+        throw new HadoopIllegalArgumentException(
+            "Expected one of -b, -k, -m, -x or --set options");
+      }
       // In recursive mode, save a separate list of just the access ACL entries.
       // Only directories may have a default ACL.  When a recursive operation
       // encounters a file under the specified path, it must pass only the

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/shell/TestAclCommands.java

@@ -64,6 +64,10 @@ public class TestAclCommands {
 
   @Test
   public void testSetfaclValidations() throws Exception {
+    assertFalse("setfacl should fail without options",
+        0 == runCommand(new String[] { "-setfacl", "/" }));
+    assertFalse("setfacl should fail without options -b, -k, -m, -x or --set",
+        0 == runCommand(new String[] { "-setfacl", "-R", "/" }));
     assertFalse("setfacl should fail without path",
         0 == runCommand(new String[] { "-setfacl" }));
     assertFalse("setfacl should fail without aclSpec",