Feature request : Tab-completion for 'shell-comand'

[paul r]

M-x shell-command, as well as its relatives (shell-command-on-region,
grep, grep-find, compile and maybe more), do not provide any kind of
completion in the minibuffer. This is a surprising behaviour, because
almost any other interactive function prompting for something that can
be tab-completed do provide tab-completion.
TSUCHIYA Masatoshi wrote an enhancement for it, that can be found
http://namazu.org/~tsuchiya/elisp/shell-command.el . This code works
against current head.
What do you think about adding the author to this thread ( if the
mailing-list rules allow it ) and discussing a possible inclusion ?