tree fa668d92873b1f1d1df22bb992610ea53a69ed49
parent 624b6b6cd582d4a58f924b3e1677628bd8260349
author Tao Bao <tbao@google.com> 1531804199 -0700
committer Tao Bao <tbao@google.com> 1531855013 -0700

Fix the arguments passed to getopt_long(3).

The getopt_long(3) implementation in Android (upstream freebsd) expects
a null-terminated array while parsing long options with required args.

  if (long_options[match].has_arg == required_argument) {
    optarg = nargv[optind++];
  }
  ...
  if (long_options[match].has_arg == required_argument && optarg == NULL) {
    return (BADARG);
  }

This seems to make sense in practice, as getopt(3) takes the first two
arguments of argc and argv that are "as passed to the main() function on
program invocation", and both of C and C++ spec say "the value of
argv[argc] shall be 0".

Prior to the CL, we may run into undefined behavior on malformed input
command line (e.g. missing arg for an option that requires one). This CL
fixes the issue by always appending a nullptr to the argument list (but
without counting that into argc).

Test: Build and boot into recovery with commands.
Change-Id: Ic6c37548f4db2f30aeabd40f387ca916eeca5392