Re: Unset array doesn't work

[Nikolai Kondrashov]

Hi Chet,

On 02/12/2018 01:31 AM, Chet Ramey wrote:
> On 2/11/18 1:06 PM, Nikolai Kondrashov wrote:
> > Hi everyone,
> >
> > I think I'm hitting a bug in Bash 4.4.12 (on Debian Stable): at some point
> > an "unset" of a global array variable doesn't work inside a function, in
> > "dkms" script from DKMS package. Adding another "unset" of the same variable
> > next to it fixes the issue.
>
> Do you have a local variable with the same name "shadowing" the global?

Thank you for the quick response!

Looking more into this, the variable in question is defined as a local in the
calling function and is being "unset" in a function called from that one.

I think this is what's happening and seems to reproduce the issue:

    #!/bin/bash

    inner() {
        unset res
        if [[ $1 == "set" ]]; then
            res[0]="X"
            res[1]="Y"
        fi
    }

    outer() {
        local res=
        inner "$1"
        echo "res: ${res[@]}"
    }

    outer set
    outer dontset

The produced output is this:

    res: X Y
    res: X Y

The expected output is this:

    res: X Y
    res:

Sorry, if this is not minimal enough. Had little time to whittle it down.

This seems to me rather a gray area, and I wouldn't be too surprised if this
was by design, but it does feel wrong.

Thank you.

Nick