"with attachment" filter fails on some fts engines

[exi]

Prerequisites

• [X] I have searched for duplicate or closed issues
• [X] I can recreate the issue with all plugins disabled

Describe the issue

The standard email filter with attachment uses an imap filter for header content-type with value multipart/m, which assumes that whatever search engine is used does an implicit wildcard search for multipart/m*, which is not always the case, for example with fts_xapian in dovecot.

The IANA mime type list only lists one sensible multi part type which matches this and that's multipart/mixed.

Could we change the roundcube filter to match exactly multipart/mixed here to allow for wider fts engine support?

What browser(s) are you seeing the problem on?

Chrome, Edge, Firefox, Safari

What version of PHP are you using?

V8.2

What version of Roundcube are you using?

V1.7

JavaScript errors

No response

PHP errors

No response

[alecpl]

I guess we can change that.

In git-master we use 'application/', 'multipart/m', 'multipart/signed', 'multipart/report'. Is 'application/' not an issue?

[exi]

@alecpl

Is 'application/' not an issue?

I have no idea, i just noticed that my attachments with multipart/mixed don't show up. I have not tested/checked application/ yet but I would think that within an email, if there is any text at all, it will always be multipart/*.

[exi]

@alecpl Would you like me to send a pullrequest with the changes i already applied locally, or do you just change it yourself?

[alecpl]

Fixed.