Re: [PATCH] local_builtin: do not overwrite previously saved options with local -

[Emanuele Torre]

On Mon, Feb 06, 2023 at 10:18:30AM -0500, Dale R. Worley wrote:
> The behavior of bash appears to be is "future changes in shell options
> using the 'set' builtin inside the current function invocation are
> restored to their prior values when the function returns".

Perhaps, the wording of the documentation is not great, but I don't
think it would make sense to expect `set -C; local -' to only set
noclobber in the dynamic scope of the current function, instead of the
previous scope.

`var=foo; local var; var=bar' works the same way, but running
`local var' after that does set var to "bar" in the previous scope.

With the current implementation, calling  local -  a second time
"commits" the changes to shell options happened after the previous
local -  call.

This patch simply makes multiple calls to  local -  a no-op to match the
behaviour of  local -  in other shells, and avoid nasty surprises.

 emanuele6