Re: Subscript flag (i) not working correctly on empty strings?

[Peter Stephenson <p.w.stephenson@ntlworld.com>]

On Fri, 2023-01-06 at 10:12 -0800, Bart Schaefer wrote:
> On Fri, Jan 6, 2023 at 9:24 AM Peter Stephenson
> <p.w.stephenson@ntlworld.com> wrote:
> > 
> > > On 06/01/2023 16:01 Philippe Altherr <philippe.altherr@gmail.com> wrote:
> > > 
> > > > s=; echo $s[(i)z];
> > > > 0
> > > 
> > > Why is the last line 0 and not 1?
> > 
> > Certainly looks plain wrong.
> > None of the existing tests fail with this change.
> 
> I thought there was a discussion about this at some point in the past
> ... but it may have been limited to array cases.  I have the feeling
> we concluded that (i) and (I) should produce the same result on empty
> string for purposes of boolean tests, but I can't find such a
> conversation in the archives.

Can you think of any piece of shell code that might rely on this,
in the absence of any historical corpus?  As far as I can see
this is a plain misuse of (i), which isn't there for boolean tests.

This doesn't feel to me like a big issue anyway and in the absence of a
clear cut reason I would think consistency should triumph.

pws