Re: New word splitting semantics for kvpair compound assignment

On Mon, Aug 17, 2026 at 10:35 AM Chet Ramey <[email protected]> wrote:
>
> Please test it out and let me know what you think, and what should change.

Configuration Information [Automatically generated, do not change]:
Machine: x86_64
OS: cygwin
Compiler: gcc
Compilation CFLAGS: -g -O2
uname output: MSYS_NT-10.0-26200 ZackFramework16
3.6.10-8fbd9808.x86_64 2026-08-13 11:15 UTC x86_64 Msys
Machine Type: x86_64-pc-cygwin

Bash Version: 5.3
Patch Level: 0
Release Status: maint

git commit 2f7eb80c77

This has no effect on key-value pair compound assignment as part of a
declaration command.

$ declare -p BASH_VERSION
declare -- BASH_VERSION="5.3.0(1)-maint"
$ declare -a kv=( zero 0 one 1 two 2 three 3 four 4 )
$ declare -A assoc
$ assoc=( "${kv[@]}" )
$ declare -p assoc
declare -A assoc=([four]="4" [two]="2" [three]="3" [one]="1" [zero]="0" )
$ declare -A assoc_copy1=( "${assoc[@]@k}" )
$ declare -p assoc_copy1
declare -A assoc_copy1=(["four 4 two 2 three 3 one 1 zero 0"]="" )
$ assoc_func () {
>   local -A assoc_copy2=( "${assoc[@]@k}" )
>   declare -p assoc_copy2
> }
$ assoc_func
declare -A assoc_copy2=(["four 4 two 2 three 3 one 1 zero 0"]="" )
$ readonly -A assoc_copy3=( "${assoc[@]@k}" )
$ declare -p assoc_copy3
declare -Ar assoc_copy3=(["four 4 two 2 three 3 one 1 zero 0"]="" )
$ export -A assoc_copy4=( "${assoc[@]@k}" )
$ declare -p assoc_copy4
declare -Ax assoc_copy4=(["four 4 two 2 three 3 one 1 zero 0"]="" )

I know that bash by default can't actually export indexed or
associative arrays into the environment, but was that last bit just
undocumented behavior, or was that not supposed to happen at all?

$ export -a kv_copy1=( "${kv[@]}" )
$ declare -p kv_copy1
declare -ax kv_copy1=([0]="zero" [1]="0" [2]="one" [3]="1" [4]="two"
[5]="2" [6]="three" [7]="3" [8]="four" [9]="4")

:/

I have a hard time believing that anyone would take advantage of the
prior key-value pair compound assignment behavior. I don't see a point
to the new kvpair_split shopt option.

The description of the readonly command in the devel branch doc/bash.1
includes a little typo:
> This sets the value of the variable ~~is~~ to value while modifying the readonly attribute.

Zack