Re: popd always has return status 0

[Pierre Gaston]

On Fri, Dec 2, 2011 at 2:01 AM,  <james.cuzella@lyraphase.com> wrote:
> Configuration Information [Automatically generated, do not change]:
> Machine: x86_64
> OS: linux-gnu
> Compiler: gcc
> Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='x86_64' 
> -DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='x86_64-pc-linux-gnu' 
> -DCONF_VENDOR='pc' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' -DSHELL 
> -DHAVE_CONFIG_H   -I.  -I../bash -I../bash/include -I../bash/lib   -g -O2 
> -Wall
> uname output: Linux cirrus 3.0.0-13-generic #22-Ubuntu SMP Wed Nov 2 13:27:26 
> UTC 2011 x86_64 x86_64 x86_64 GNU/Linux
> Machine Type: x86_64-pc-linux-gnu
>
> Bash Version: 4.2
> Patch Level: 10
> Release Status: release
>
> Description:
>        popd does not appear to return a nonzero exit status when the 
> directory stack is empty anymore.  The bash manual says the following for 
> popd:
>
>        "If the popd command is successful, a dirs is performed as well, and 
> the return status is 0.  popd returns false if an invalid option is 
> encountered, the directory stack is
>                      empty, a non-existent directory stack entry is 
> specified, or the directory change fails."
>
>        I am seeing this problem on: Ubuntu 11.10 oneiric
>               bash package version: 4.2-0ubuntu4
>
> Repeat-By:
>        Put some directories on the stack with pushd, then call popd and check 
> the return status.  It is expected to be nonzero when the stack is empty or 
> an error occurs.
>        The following function should pop all dirs off the stack and then 
> stop, however the while loop continues infinitely:
>
>        popall ()
>        {
>                local not_done=0;
>                while [ $not_done -eq 0 ]; do
>                        popd;
>                        not_done=$?;
>                done
>        }
>

I don't seem to be able to reproduce this:

$ dpkg-query --show bash
bash    4.2-0ubuntu4
$ echo $BASH_VERSION
4.2.10(1)-release
$ declare -f popall
popall ()
{
    local not_done=0;
    while [ $not_done -eq 0 ]; do
        popd;
        not_done=$?;
    done
}

$ pushd test
~/test ~
$ popall
~
bash: popd: directory stack empty
$