Bash 4.3 handles array variables in sourced scripts differently than 4.2

[Ewan Mellor]

Hi,

Please cc me ‹ I¹m not subscribed to this list.

I have a script that works correctly in Bash 4.2.25(1)-release from Ubuntu
12.04 (package version 4.2-2ubuntu2) but that fails in Bash
4.3.0(1)-release from Ubuntu 14.04 prerelease (package version
4.3-2ubuntu1).

The root of the problem is that I am using declare ­a inside a script that
is sourced.  In 4.2 this variable is still available in the outer scope.
In 4.3 it is not, and I get an error when I try to use it.

I haven¹t checked whether this is specific to array variables or whether
it applies to other uses of declare too.

Is this a known issue?  It¹s not mentioned in COMPAT or the FAQ that I
could find.  All help appreciated!

Thanks,

Ewan.


deploy.sh:

#!/bin/bash

set -eu

. /usr/lib/tipbit/git_management.sh

update_repo "/srv" www.tipbit.com www.tipbit.com production >/dev/null


/usr/lib/tipbit/git_management.sh:

update_repo()
{
 (repo_parent_dir="$1"
  repo_dest_name="$2"
  repo_source_name="$3"
  branch="$4"

  repo_dest_dir="$repo_parent_dir/$repo_dest_name"

  . /usr/lib/tipbit/on_exit.sh

  eval $(ssh-agent) >/dev/null
  printf 'notasecret\n' | monkeysphere subkey-to-ssh-agent >/dev/null 2>&1
  add_on_exit "kill $SSH_AGENT_PID²

  # Script proceeds...
 )
}


/usr/lib/tipbit/on_exit.sh:

#!/bin/bash

declare -a on_exit_hooks

on_exit()
{
    for i in $(seq $((${#on_exit_hooks[*]} - 1)) -1 0)
    do
        eval "${on_exit_hooks[$i]}"
    done
}

add_on_exit()
{
    local n=${#on_exit_hooks[*]}
    on_exit_hooks[$n]="$*"
    if [[ $n -eq 0 ]]
    then
        trap on_exit EXIT
    fi
}


Trace from Bash 4.3:

$ bash -x ./deploy-tipbit.com.sh
+ set -eu
+ . /usr/lib/tipbit/git_management.sh
+ update_repo /srv www.tipbit.com www.tipbit.com production
+ repo_parent_dir=/srv
+ repo_dest_name=www.tipbit.com
+ repo_source_name=www.tipbit.com
+ branch=production
+ repo_dest_dir=/srv/www.tipbit.com
+ . /usr/lib/tipbit/on_exit.sh
++ declare -a on_exit_hooks
++ ssh-agent
+ eval 'SSH_AUTH_SOCK=/tmp/ssh-EQr2YBnPE5K7/agent.9147;' export
'SSH_AUTH_SOCK;' 'SSH_AGENT_PID=9148;' export 'SSH_AGENT_PID;' echo Agent
pid '9148;'
++ SSH_AUTH_SOCK=/tmp/ssh-EQr2YBnPE5K7/agent.9147
++ export SSH_AUTH_SOCK
++ SSH_AGENT_PID=9148
++ export SSH_AGENT_PID
++ echo Agent pid 9148
+ monkeysphere subkey-to-ssh-agent
+ printf 'notasecret\n'
+ add_on_exit 'kill 9148'
/usr/lib/tipbit/on_exit.sh: line 19: on_exit_hooks: unbound variable



Trace from Bash 4.2:

$ bash -x ./deploy-tipbit.com.sh
+ set -eu
+ . /usr/lib/tipbit/git_management.sh
+ update_repo /srv www.tipbit.com www.tipbit.com production
+ repo_parent_dir=/srv
+ repo_dest_name=www.tipbit.com
+ repo_source_name=www.tipbit.com
+ branch=production
+ repo_dest_dir=/srv/www.tipbit.com
+ . /usr/lib/tipbit/on_exit.sh
++ declare -a on_exit_hooks
++ ssh-agent
+ eval 'SSH_AUTH_SOCK=/tmp/ssh-QrkegAwJO322/agent.322;' export
'SSH_AUTH_SOCK;' 'SSH_AGENT_PID=323;' export 'SSH_AGENT_PID;' echo Agent
pid '323;'
++ SSH_AUTH_SOCK=/tmp/ssh-QrkegAwJO322/agent.322
++ export SSH_AUTH_SOCK
++ SSH_AGENT_PID=323
++ export SSH_AGENT_PID
++ echo Agent pid 323
+ monkeysphere subkey-to-ssh-agent
+ printf 'notasecret\n'
+ add_on_exit 'kill 323'
+ local n=0
+ on_exit_hooks[$n]='kill 323'
+ [[ 0 -eq 0 ]]
+ trap on_exit EXIT
# Script proceeds...