Re: Weird problem with git-submodule.sh

From: Junio C Hamano <gitster@pobox.com>
Date: Dec 7, 2012, 20:23 UTC
Message-ID: <7vsj7hfw6q.fsf@alter.siamese.dyndns.org>
In-Reply-To: <50C24ED7.90000@xiplink.com>

Marc Branchaud <marcnarc@xiplink.com> writes:

Show 17 quoted lines

>     sh-setup: protect from exported IFS
>
>     Many scripted Porcelains rely on being able to split words at the
>     default $IFS characters, i.e. SP, HT and LF.  If the user exports a
>     non-default IFS to the environment, what they read from plumbing
>     commands such as ls-files that use HT to delimit fields may not be
>     split in the way we expect.
>
>     Protect ourselves by resetting it, just like we do so against CDPATH
>     exported to the environment.
>
>     Noticed by Andrew Dranse <adranse@oanda.com>.
>
>     Signed-off-by: Junio C Hamano <gitster@pobox.com>
>
> Perhaps IFS should be set to " \t\n" (which I believe is sh's default)
> instead of just unsetting it altogether?

POSIX.1 says this:

    IFS - A string treated as a list of characters that is used for
    field splitting and to split lines into fields with the read
    command.  If IFS is not set, it shall behave as normal for an
    unset variable, except that field splitting by the shell and
    line splitting by the read command shall be performed as if the
    value of IFS is <space> <tab> <newline>; see Field Splitting.

    Implementations may ignore the value of IFS in the environment, or
    the absence of IFS from the environment, at the time the shell is
    invoked, in which case the shell shall set IFS to <space> <tab>
    <newline> when it is invoked.

So setting it to SP HT LF should not make a difference, or your shell is buggy.

This is exactly why I asked you about the /bin/sh on your problematic box.