Re: [PATCH] Fix crash on unset-through-nameref

[Stephane Chazelas <stephane@chazelas.org>]

2024-03-05 15:16:25 -0800, Bart Schaefer:
[...]
> Sorry, your example is confusing me.  "nameref" is only available when
> the zsh/ksh93 module is loaded.  What's actually happening here, and
> why do you never use -fc to prevent dotfiles from being read?

I hadn't realised -f also skipped ~/.zshenv, I thought that one
like /etc/zshenv could not be skipped (and why I always leave it
empty as it also affects scripts).

Should we also use

#! /bin/zsh -f-

shebangs in scripts?

> I think you're referring to the difference between
>   var=0; f
> and simply
>   f
> In the latter case, "the scope where it completed the resolve" is the
> local scope because no parameter in a surrounding scope exists.  If
> you assign to such a nameref, it "goes first to that scope", and if it
> still finds nothing, climbs up to global scope (because implicitly
> "finds nothing" at any local scope means there can't be that name at
> global scope).
> 
> It's consistent with how $var / var=x would work if you never declared
> anything, and consistent with ${(P)ptr} / ${(P)ptr::=x} when ptr is a
> plain scalar.  The difference is when the ref has already found
> something, which seems like the intended difference if you're using a
> reference in the first place.

My point is that if it means the:

assign() {
  typeset -n var=$1
  local value=$2
  var=$value
}

doesn't work for

assign var value
or
assign value something

And we need to work around it by doing:

assign() {
  typeset -n _assign_var=$1
  local _assign_value=$2
  _assign_var=$_assign_value
}

(Yes, I know we can always fo assign() eval -- $1=\$2)

Like we do in bash/mksh or when using (P) or eval... then
there's little point trying to be smarter in the

var=; assign var value
value=; assign value something

cases. You may say there's no harm in doing so, I'd agree
there's little harm except
- it makes it a bit inconsistent
- it may trick users into thinking they can get away without
  using namespacing.

In any case, I'm not against being smart in the second case, I
just wish we could get away without the namespacing (like in the
zslurp case which started that whole discussion).

-- 
Stephane