Bash - Can't copy associative array if piping block output to command

Question

With the following code I can't clone the associative array in Bash if piping to a command. I'm using Whiptail to display a progress bar:

#!/bin/bash 

declare -Ar ARR1=(
[a]='asdf'
[b]='qwerty'
[c]='yuio'
)

declare -A ARR2=()

clone() {
    {
        for key in "${!ARR1[@]}"; do
            ARR2[$key]="${ARR1[$i]}"

            echo "10"  # Hardcoded percentage for Whiptail
        done
    } | whiptail --gauge "Cloning" 6 60 0
}

clone

for key in "${!ARR2[@]}"; do
  echo "$key"
  echo "${ARR2[$i]}"
done

Removing the Whiptail pipe it works:

#!/bin/bash 

declare -Ar ARR1=(
[a]='asdf'
[b]='qwerty'
[c]='yuio'
)

declare -A ARR2=()

clone() {
    {
        for key in "${!ARR1[@]}"; do
            ARR2[$key]="${ARR1[$i]}"

            echo "10"  # Hardcoded percentage for Whiptail
        done
    }
}

clone

for key in "${!ARR2[@]}"; do
  echo "$key"
  echo "${ARR2[$i]}"
done

Is there a way to make this work with the Whiptail pipe?

Answer 1

Would you please try the following:

#!/bin/bash

declare -Ar ARR1=(
    [a]='asdf'
    [b]='qwerty'
    [c]='yuio'
)

declare -A ARR2=()

clone() {
    {
        n=${#ARR1[*]}                   # number of items
        for key in "${!ARR1[@]}"; do
            ARR2[$key]="${ARR1[$key]}"
            (( i++ ))                   # increment a counter
            echo $(( 100 * i / n ))     # percentage
            sleep 1                     # wait for 1 sec
        done
    } > >(whiptail --gauge "Cloning" 6 60 0)
}

clone

for key in "${!ARR2[@]}"; do
    echo "$key"
    echo "${ARR2[$key]}"
done

The key is the } > >(whiptail ... expression which keeps the enclosed block in the foreground process without using a pipeline.
Please note that I have modified the code to display percentage to make it look like that.