Re: [exim] Empty variable expansion in header

On 01/04/2021 21:55, Leonhardt,Christian via Exim-users wrote:
> ---
> 2021-04-01 22:15:27 1lS3ix-0008Rl-IC LEO: We found an extension (test.ppt) that we dont trust. Setting acl_m_block1 for later processing
> 2021-04-01 22:15:27 1lS3ix-0008Rl-IC LEO: We found an extension (test.leotest) that we dont trust. Setting acl_m_block1 for later processing
> 2021-04-01 22:15:27 1lS3ix-0008Rl-IC LEO: We found an extension (test.xls) that we dont trust. Setting acl_m_block1 for later processing
> ---
>
> But in the MUA mailbox one occurrence is always missing in the header.
>
> ---
> X-Test-Suspicious:
> X-Test-Suspicious: test.ppt
> X-Test-Suspicious: test.leotest
> ---
>
> Sending just one suspicious attachment always results in an empty "X-Test-Suspicious:"
> What am I doing wrong here?

Trying to add the same header multiple times. Per the ACL docs chapter,
section 24:

"Further header lines may be accumulated during the DATA and MIME ACLs,
after which they are added to the message, again with duplicates suppressed".

- so you've probably found a bug too; that deduplication isn't working right.
Please raise a bug for that.

I suggest appending to your variable in the MIME ACL, generating a
list of dodgy file names seen. Then if non-empty in the DATA ACL, add the header
there (once).
--
Cheers,
Jeremy