su: allow additional arguments after su -csu_cmd

The syntax becomes:

  su [-c CMD [ARG...]]

This makes it a lot easier to use values from the current shell,
instead of shell-quoting them for re-input and embedding at CMD.

Also, previously -c expected an option-argument, and now it's a flag
which requires a CMD operand, just like 'sh', so that both these
forms now error the same way (as they should):

   sh -c --
   su -c --

(previously su -c -- did not error because '--' was assumed CMD)

Adds 64 bytes.

(Based on GitHub PR #317)

0 files changed, 0 insertions, 0 deletions