​Configuration Information [Automatically generated, do not change]:Machine:
x86_64OS: linux-muslCompiler: gccCompilation CFLAGS: -g -O2 -Wno-parentheses
-Wno-format-securityuname output: Linux 37b7613044c1 5..5.7-200.fc31.x86_64 #1
SMP Fri Feb 28 17:18:37 UTC 2020 x86_64 GNU/LinuxMachine Type:
x86_64-pc-linux-musl
Bash Version: 5.1Patch Level: 0Release Status: alpha
Description: Declaring an array and setting it with
empty strings ("") in one line is bugged in bash 5.1 alpha. This has worked in
bash 3.2-5.0 without issue.
I first discovered this through a piece of
indirection code I have:
x=("") y="x[@]"
local z=(${!y+"${!y}"})
Repeat-By: docker run -it --rm bash:5.1-alpha
bash -c 'function foo(){ local bug=("" "5" "" 1 ""); declare -a bug2=("");
declare -ga bug3=("" "5" "" 1 ""); local not_bug=("no" "nulls"); local
workaround; workaround=(""); declare -p bug bug2 bug3 not_bug workaround; };
declare -a bug4=("" "5" "" 1 ""); declare -p bug4; foo'
Results: declare -a
bug4=([0]="5" [1]="1") declare -a bug=([0]="5"
[1]="1") declare -a bug2=()
declare -a bug3=([0]="5" [1]="1") declare -a
not_bug=([0]="no" [1]="nulls") declare -a
workaround=([0]="")
As you can see, all the empty strings (null
strings) are missing, except in the workaround
Fix: Declaring an array with empty strings ("") in
one line should work, just like it did in bash 3.2-5.0
This original piece of code should also work the
same as versions 3.2-5.0 too
$ docker run -it --rm bash:5.0 bash -euc 'function
foo(){ local name="${1}[@]"; local copy=(${!name+"${!name}"}); declare -p copy;
}; x=("" 5 ""); foo x; foo undeclared_x' declare -a
copy=([0]="" [1]="5" [2]="") declare -a copy=()
$ docker run -it --rm bash:5.1-alpha bash -euc
'function foo(){ local name="${1}[@]"; local copy=(${!name+"${!name}"});
declare -p copy; }; x=("" 5 ""); foo x; foo undeclared_x'
declare -a copy=([0]="5") declare -a copy=()
