MDEV-22983: Mariabackup's --help option disappeared

return --help option

extra/mariabackup/xtrabackup.cc

@@ -119,6 +119,7 @@ my_bool xtrabackup_move_back;
 my_bool xtrabackup_decrypt_decompress;
 my_bool xtrabackup_print_param;
 my_bool xtrabackup_mysqld_args;
+my_bool xtrabackup_help;
 
 my_bool xtrabackup_export;
 
@@ -1458,6 +1459,11 @@ struct my_option xb_server_options[] =
      (G_PTR *) &xtrabackup_mysqld_args, (G_PTR *) &xtrabackup_mysqld_args, 0,
      GET_BOOL, NO_ARG, 0, 0, 0, 0, 0, 0},
 
+    {"help", '?',
+     "Display this help and exit.",
+     (G_PTR *) &xtrabackup_help, (G_PTR *) &xtrabackup_help, 0,
+     GET_BOOL, NO_ARG, 0, 0, 0, 0, 0, 0},
+
   { 0, 0, 0, 0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0}
 };
 

mysql-test/suite/mariabackup/options_check.result

@@ -5,3 +5,4 @@
 # Check for options overwriting
 # Check if uknown options that follow --mysqld-args are ingored
 # Check if [mariadb-client] group is not loaded (MDEV-22894)
+# Check if --help presents

mysql-test/suite/mariabackup/options_check.test

@@ -7,7 +7,6 @@
 exec $XTRABACKUP --defaults-file=$MYSQLTEST_VARDIR/my.cnf --backup --unknown-option=xxx --target-dir=$targetdir;
 --error 2
 exec $XTRABACKUP --defaults-file=$MYSQLTEST_VARDIR/my.cnf --backup --unknown-option --target-dir=$targetdir;
---enable_result_log
 
 --echo # Check for unknown options in "mariabackup" group
 --write_file $custom_cnf
@@ -62,3 +61,9 @@ EOF
 exec $XTRABACKUP --defaults-file=$custom_cnf --backup --target-dir=$targetdir;
 --remove_file $custom_cnf
 --rmdir $targetdir
+
+--echo # Check if --help presents
+exec $XTRABACKUP --help;
+exec $XTRABACKUP -?;
+--enable_result_log
+