[PATCH] board: toradex: Quote variables in `test` cmd expression

[Francesco Dolcini]

+Simon

Hello Tom,

On Thu, Apr 09, 2026 at 11:07:31AM +0200, Rasmus Villemoes wrote:
> On Fri, Apr 03 2026, Francesco Dolcini <francesco at dolcini.it> wrote:
> > On Thu, Apr 02, 2026 at 05:30:29PM -0600, Tom Rini wrote:
> >> On Wed, Apr 01, 2026 at 07:10:27AM +0200, Francesco Dolcini wrote:
> >> > On Tue, Mar 31, 2026 at 10:10:10AM +0200, Franz Schnyder wrote:
> >> > > From: Franz Schnyder <franz.schnyder at toradex.com>
> >> > > 
> >> > > With correct POSIX handling, unquoted empty variables can turn the
> >> > > expression like
> >> > > 	test -n ${fdtfile}
> >> > > into
> >> > > 	test -n
> >> > > 
> >> > > The POSIX handling for single argument `test` evaluates it as true,
> >> > > so the fallback initialization will be skipped unexpectedly.
> >> > > Quoting variable expansions in `test` expressions will always result in
> >> > > correct behavior for empty and non-empty values.
> >> > > This change was triggered by
> >> > > commit 8b0619579b22 ("cmd: test: fix handling of single-argument form of test")
> >> > > The aim is to have a less fragile codebase that is not dependent on a
> >> > > quirk of the shell implementation.
> >> > > 
> >> > > Use quoted variable expansions in `test` expressions throughout.
> >> > > 
> >> > > Signed-off-by: Franz Schnyder <franz.schnyder at toradex.com>
> >> > 
> >> > Acked-by: Francesco Dolcini <francesco.dolcini at toradex.com>
> >> 
> >> I've decided to go with:
> >> https://patchwork.ozlabs.org/project/uboot/patch/20260330140106.401876-1-ravi@prevas.dk/
> >> to make sure that everyone that might hit this problem doesn't end up
> >> broken, thanks.
> >
> > I am wondering if you should apply this in any case. This change is generally correct.
> 
> I agree. And note that this really isn't anything to do with the 'test'
> command per se, it's simply that using any variable whose value can be
> empty or contain spaces is prone to produce something other than exactly
> 1 word, exactly as in userspace shell, and once the shell has done its
> parsing and word splitting, the called command really has no way of
> knowing that there's an empty argument missing.

Tom? I think this should be applied, see also the related change from
Simon.

Francesco