[pmg-devel] [PATCH pmg-api v4 3/5] pmg-smtp-filter: archive-detection: use header information as well

[Dominik Csapak]

On 2/20/25 21:13, Stoiko Ivanov wrote:
> This restores the fall-back to the content-type from the header for
> detecting archives, which we want to unpack, as eagerly trying to get
> all information seems sensible in this case.
> 
> Signed-off-by: Stoiko Ivanov <s.ivanov at proxmox.com>
> ---
>   src/bin/pmg-smtp-filter | 10 ++++++++--
>   1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/src/bin/pmg-smtp-filter b/src/bin/pmg-smtp-filter
> index 6061459..6c03631 100755
> --- a/src/bin/pmg-smtp-filter
> +++ b/src/bin/pmg-smtp-filter
> @@ -561,9 +561,15 @@ sub run_dequeue {
>   sub unpack_entity {
>       my ($self, $unpack, $entity, $msginfo, $queue) = @_;
>   
> -    my ($magic, $path) = $entity->@{'PMX_magic_ct', 'PMX_decoded_path'};
> +    my ($magic, $headerct, $path) = $entity->@{'PMX_magic_ct', 'PMX_header_ct', 'PMX_decoded_path'};
> +
> +    if ($path) {

while not really wrong (currently, since $path and $magic are always set or unset together)
not checking for $magic here sets us up for future bugs

we use both in the branch (independently of one another), so if some codechange in the future
would set $path but not $magic, we'd enter the branch with '$magic = undef' here unintentionally

so keeping the `if ($magic && $path)` here does not hurt us, and only makes
it clearer that both must be set for the branch to be executed..

> +	# in order to not miss information from a misdetected archive use information provided in the
> +	# header here as well
> +	if ($headerct && ($magic && $magic eq 'application/octet-stream')) {
> +	    $magic = $headerct;
> +	}
>   
> -    if ($magic && $path) {
>   	my $filename = basename ($path);
>   
>   	if (PMG::Unpack::is_archive ($magic)) {