[pbs-devel] applied: [PATCH pxar] decoder: fix incorrect accounting for header in payload input

[Fabian Grünbichler]

thanks (and also thanks for the reminder!)

On September 18, 2024 5:00 pm, Christian Ebner wrote:
> Payload entries are separated by headers of type PAYLOAD within the
> payload stream of split pxar archives, used for consistency checks
> when accessing the file contents via a reader instance.
> 
> Commit 5b8204d0 moved these consistency checks, so they only happen
> when actually accessing the content, thereby drastically improving
> performance when navigating contents via the metadata archive.
> 
> The commit however also incorrectly increased the `Decoder`s
> `payload_consumed` field by the size of the header, in case the file
> payload has not been accessed by the `content_reader`.
> 
> As this filed is used to account for consumed bytes while sequentially
> reading to possibly skip over entries, this leads to incorrectly
> skipping of bytes in the stream (less than required). The main
> manifestation being that a pxar extract with provided match pattern
> failed.
> 
> Therefore, drop the incorrect accounting of the payload header.
> 
> Fixes: 5b8204d0 ("decoder: move payload header check for split input")
> 
> Signed-off-by: Christian Ebner <c.ebner at proxmox.com>
> ---
> Stumbled accorss this one while working on issue 2996.
> Without this a
> ```
> pxar extract archive.mpxar target --payload-input archive.ppxar
> --pattern <some-pattern>
> ```
> will fail the payload header checks.
> 
>  src/decoder/mod.rs | 5 -----
>  1 file changed, 5 deletions(-)
> 
> diff --git a/src/decoder/mod.rs b/src/decoder/mod.rs
> index 6191627..613ec12 100644
> --- a/src/decoder/mod.rs
> +++ b/src/decoder/mod.rs
> @@ -299,14 +299,9 @@ impl<I: SeqRead> DecoderImpl<I> {
>                  }
>                  State::InPayload {
>                      offset,
> -                    header_checked,
>                      ..
>                  } => {
>                      if self.input.payload().is_some() {
> -                        if !header_checked {
> -                            // header is only checked if payload has been accessed
> -                            self.payload_consumed += size_of::<Header>() as u64;
> -                        }
>                          // Update consumed payload as given by the offset referenced by the content reader
>                          self.payload_consumed += offset;
>                      } else {
> -- 
> 2.39.2
> 
> 
> 
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