Re: [PATCH] PublicInbox::Import Extend add with a optional raw message parameter

[ebiederm@xmission.com (Eric W. Biederman)]

Eric Wong <e@80x24.org> writes:

> "Eric W. Biederman" <ebiederm@xmission.com> wrote:
>> 
>> I don't trust the MIME type to not munge my email messages in horrible
>> ways upon occasion.  Therefore  allow for passing in the raw message
>> value instead of trusting the mime object to preserve it.
>> 
>> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
>
> I've had the same concern in the past about Email::MIME and
> Email::Simple.  But after reading the code for Email::MIME,
> Email::Simple and Email::{MIME,Simple}::Header, I don't think
> the implementation of Email::MIME->as_string and all methods it
> calls does anything unreasonable.
>
> The only notable munging they seem to do is make irrelevant
> whitespace changes in headers and maybe fix quoting in headers.
> No body changes AFAIK.

I was hoping I could skip the Email::MIME stuff entirely but the headers
do need a bit of parsing to derive the git commit information.

I will take a second look at the code.  I did not make it all of the
way through last time.  I just know the bazillions of warnings I could
not easily track down with old emails did not make me comfortable
with that code base as anything other than a suggestion.

>> The context here is because the only copy of messages that I save
>> I save in public-inbox I don't want to have to worry about losing
>> information.  So I just pass the raw email_str to add.
>> 
>> I expect if I were to export these lists public I would want to do
>> some more but for now I am just putting them in public-inbox
>> so that I can read and archive the lists locally.
>
> I worry about public archives getting badly munged, too.
>
>>  lib/PublicInbox/Import.pm     | 10 +++++-----
>>  lib/PublicInbox/V2Writable.pm |  8 ++++----
>>  2 files changed, 9 insertions(+), 9 deletions(-)
>
> Did you have plans to modify -mda/-watch or another script to
> use this?

I have been using this for a while with my own imap fetcher
script.  As for the others I certain could.  I don't use -mda
or -watch so they have not been a priority.

>> diff --git a/lib/PublicInbox/Import.pm b/lib/PublicInbox/Import.pm
>> index 81a38fb6987d..0a63784414f2 100644
>> --- a/lib/PublicInbox/Import.pm
>> +++ b/lib/PublicInbox/Import.pm
>> @@ -359,7 +359,7 @@ sub clean_tree_v2 ($$$) {
>>  # returns undef on duplicate
>>  # returns the :MARK of the most recent commit
>>  sub add {
>> -	my ($self, $mime, $check_cb) = @_; # mime = Email::MIME
>> +	my ($self, $mime, $check_cb, $email_str) = @_; # mime = Email::MIME
>
> I usually place callback args at the end of the arg list so
> it's easy to write:
>
> 	$im->add($mime, sub {
> 		# ...
> 	});
>
> So having a parameter after the sub{} is a bit ugly...
> If I had to support this, I think I'd accept $mime being
> a plain hashref:
>
> 	if (ref($mime) eq 'HASH') {
> 		$raw = $mime->{raw};
> 		$mime = $mime->{mime};
> 	} else {
> 		$raw = $mime->as_string;
> 	}
>
> But, I'm still on the fence about the idea...
>
> Side note: I'm also taking the opportunity to use "$raw" instead
> of "$str", because I've been bitten by the difference header_raw
> vs header_str in the Email::MIME API, so consistency with
> that API would be good, here.

Yes the distinction about "$raw" is fair,
and the placement in the argument list makes sense.

As for the hashref.  Perhaps what I should do is modify
PublicInbox::MIME to at least conditionally keep the original raw email
around.  Then the logic to get the raw email could be kept in
PublicInbox::MIME as well.

Which let's me think the general solution is to have a configuration
option somewhere that says we want to archive the raw email.  We
update PublicInbox::MIME to always keep the original raw email.

If add is not configured to drop any headers we use the raw original
email str.  If add drops any headers we do what we do today.

I think perhaps we could move all of the scrubbing into
PublicInbox::Filter::Base.pm::scrub.  Instead of having a hard coded
drop_unwanted_headers in PublicInbox::Import.  That would make it very
straight forward to just make this a knob that the user controls
for how they want their email received/imported.

If that general idea sounds palatable I will investigate to see
if I can move the caching of the raw email into PublicInbox::MIME,
see about moving the dropping of headers into an appropriate config
knob.

Eric