MDEV-19949 mariabackup option of '--password' or '-p' without specifying password in commandline

password handling as in other command-line tools

extra/mariabackup/xtrabackup.cc

@@ -373,6 +373,7 @@ my_bool opt_noversioncheck = FALSE;
 my_bool opt_decompress = FALSE;
 my_bool opt_remove_original;
 my_bool opt_log_innodb_page_corruption;
+my_bool tty_password= FALSE;
 
 my_bool opt_lock_ddl_per_table = FALSE;
 static my_bool opt_check_privileges;
@@ -1655,7 +1656,7 @@ struct my_option xb_client_options[]= {
      "This option specifies the password to use "
      "when connecting to the database. It accepts a string argument.  "
      "See mysql --help for details.",
-     0, 0, 0, GET_STR, REQUIRED_ARG, 0, 0, 0, 0, 0, 0},
+     0, 0, 0, GET_STR, OPT_ARG, 0, 0, 0, 0, 0, 0},
 
     {"protocol", OPT_PROTOCOL,
      "The protocol to use for connection (tcp, socket, pipe, memory).", 0, 0,
@@ -2333,6 +2334,7 @@ xb_get_one_option(const struct my_option *opt,
     break;
   case 'p':
     opt_password = argument;
+    tty_password = argument == NULL;
     break;
   case OPT_PROTOCOL:
     if (argument)
@@ -7332,6 +7334,8 @@ void handle_options(int argc, char **argv, char ***argv_server,
           if (*start)
             start[1]= 0;
         }
+        else if (tty_password)
+          opt_password= my_get_tty_password(NullS);
 
         /* 4) Process --mysqld-args options, ignore unknown options */