[pbs-devel] [PATCH v2 proxmox-backup] client: catalog shell: avoid navigating below archive root

[Wolfgang Bumiller]

On Thu, Aug 08, 2024 at 01:42:03PM GMT, Christian Ebner wrote:
> Avoid to underflow the catalogs shell position stack by navigating
> below the archives root directory into the catalog root. Otherwise
> the shell will panic, as the root entry is always expected to be
> present.
> 
> This threats the archive root directory as being it's own parent
> directory, mimicking the behaviour of most common shells.
> 
> Signed-off-by: Christian Ebner <c.ebner at proxmox.com>
> ---
> Encountered while implementing the catalog shell for the split pxar
> archive case.
> 
> Without this additional check, a `cd ..` in the pxar archive root of
> the catalog shell will panic.


What about `cd ../../..` when *not* at a root, would we now ignore this
without any error messages?

> 
> changes since version 1:
> - use `is_empty` to check if vector is empty
> - extend commit message and comment to clarify that archive root acts as
>   its own parent directory
> 
>  pbs-client/src/catalog_shell.rs | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/pbs-client/src/catalog_shell.rs b/pbs-client/src/catalog_shell.rs
> index 349bb7cbc..1c50cbf96 100644
> --- a/pbs-client/src/catalog_shell.rs
> +++ b/pbs-client/src/catalog_shell.rs
> @@ -720,6 +720,13 @@ impl Shell {
>                      &mut None,
>                  )
>                  .await?;
> +
> +                if new_position.is_empty() {
> +                    // Avoid moving below archive root into catalog root, thereby treating
> +                    // the archive root as its own parent directory.
> +                    return Ok(());
> +                }
> +
>                  if !new_position.last().unwrap().catalog.is_directory() {
>                      bail!("not a directory");
>                  }
> -- 
> 2.39.2