test: fix 4-argument case

test: fix 4-argument case

Upstream dash commit:

    Date: Sun, 13 Jul 2008 19:20:10 +0800
    Fixed 3,4-argument cases for test per POSIX

    ----- Forwarded message from Gerrit Pape <pape@smarden.org> -----

    Subject: Bug#455828: dash: 4-argument test "test \( ! -e \)" yields an error
    Date: Fri, 28 Dec 2007 08:53:29 +0000
    From: Gerrit Pape <pape@smarden.org>
    To: Vincent Lefevre <vincent@vinc17.org>, 455828@bugs.debian.org

    On Thu, Dec 27, 2007 at 06:23:20PM +0100, Vincent Lefevre wrote:
    > On 2007-12-27 16:00:06 +0000, Gerrit Pape wrote:
    > > On Wed, Dec 12, 2007 at 02:18:47AM +0100, Vincent Lefevre wrote:
    > > > According to POSIX[*], "test \( ! -e \)" is a 4-argument test and is
    > > > here equivalent to "test ! -e". But dash (like ksh93 and bash) yields
    > > > an error:
    > > >
    > > > $ test \( ! -e \) || echo $?
    > > > test: 1: closing paren expected
    > > > 2
    > > > $ test ! -e || echo $?
    > > > 1
    > >
    > > Hi Vincent,
    > >
    > > the -e switch to test takes an argument, a pathname.
    >
    > According to POSIX, in both above examples, "-e" is *not* a switch,
    > just a string.
    >
    >   test \( ! -e \)
    >
    > means: return true if the string "-e" is empty, otherwhise return false.
    > The error in dash is that it incorrectly thinks that "-e" is a switch in
    > this context.

    I see, you're right.  Thanks, Gerrit.

    ----- End forwarded message -----

    This patch hard-codes the 3,4-argument cases in the way required by
    POSIX.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
function                                             old     new   delta
test_main                                            370     421     +51

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>