fix: Guarantee immediate message deletion if delete_server_after == 0 (#5201)

[iequidoo]

This should fix most of the failures of test_verified_group_vs_delete_server_after(). But sometimes it fails in a different way, maybe we have some race in IMAP handling (see #5201 (comment)), so let's leave the issue open for now.

EDIT: Looks like this should be tested in the Rust test test_delete_expired_imap_messages().

[iequidoo]

Merging w/o a test to fix CI, will add the test soon

[adbenitez]

I am a bit confused, doesnt delete_server_after == 0 mean "do not delete, never delete" why should it be guaranteed that messages are deleted immediately? 🤔

[iequidoo]

I am a bit confused, doesnt delete_server_after == 0 mean "do not delete, never delete" why should it be guaranteed that messages are deleted immediately? 🤔

You're right, 0 is interpreted as None and this means "never delete":

    pub async fn get_config_delete_server_after(&self) -> Result<Option<i64>> {                                                                                                                                      
        match self.get_config_int(Config::DeleteServerAfter).await? {
            0 => Ok(None),
            1 => Ok(Some(0)),
            x => Ok(Some(i64::from(x))),
        }
    }

Probably, the commit message should say Some(0) instead of 0, but it's already merged :)

[adbenitez]

Thanks for explaining 👍