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Declaring arrays with empty string in one line is bugged

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​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=()

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Declaring arrays with empty string in one line is bugged andy_bash <andy_bash@objectmail.com> - 2020-08-04 19:07 +0200

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