Matrix attachment improvements

[selfhoster1312]

@poVoq @josephcrowell

Three small fixes in here. We may have differing opinion about these so feedback is welcome.

• Don't check attachment size announced in attachment payload (the HTTP server will be the ultimate source of truth)
• Treat message body, when there is an attachment, as an attachment caption because that's apparently what clients do and it was producing weird results in other bridges (such as @poVoq's empty message in Handle XMPP uploads #23)
• If an extension matching the mimetype isn't found, add it (even if it's not an image) ; if the mimetype doesn't match any extensions, drop the attachment entirely to avoid errors further down

[josephcrowell]

I've been watching you test. I want this yesterday.

[selfhoster1312]

I've been watching you test. I want this yesterday.

Hehe better late than never 👍

Btw i noticed you're not written down as maintainer of matrix bridge in docs/protocols/matrix/README.md is that on purpose @josephcrowell? Or should i add you there?

[josephcrowell]

I've been watching you test. I want this yesterday.

Hehe better late than never 👍

Btw i noticed you're not written down as maintainer of matrix bridge in docs/protocols/matrix/README.md is that on purpose @josephcrowell? Or should i add you there?

I'm not sure that I have the available time to devote that you'll need from a maintainer.

[selfhoster1312]

I'm not sure that I have the available time to devote that you'll need from a maintainer.

For now "maintainer" is relatively undefined. It's more about being pinged when a PR comes in for that bridge for review. And there's no commitment involved. I appreciate your honesty, let us know if you'd like to be registered as maintainer :)

[josephcrowell]

I'm not sure that I have the available time to devote that you'll need from a maintainer.

For now "maintainer" is relatively undefined. It's more about being pinged when a PR comes in for that bridge for review. And there's no commitment involved. I appreciate your honesty, let us know if you'd like to be registered as maintainer :)

Alright, in that case yeah go ahead and add me as a maintainer.