Dear Maintainer,

When images are posted from matrix.org homeservers, nheko can display
neither the image thumbnail nor the full-size image.  Instead, one mostly
sees the "broken image" picture in place of the thumbnail, and a black
screen when trying to load the full image.

Nheko will log something like
[2024-10-07 11:06:06.090] [net] [error] Failed to download matrix.org/iuHzUbEjGRlBxbrhPlNvHKVZ: (http: 404, matrix: M_NOT_FOUND:'Not found')
on entering a room where such an image is part of the conversation.

Other clients, eg element on Android, show both thumbnail and image just fine.

This was logged as a bug with upstream, at https://github.com/Nheko-Reborn/nheko/issues/1806 ,
and the head dev pointed us to a policy change with the matrix.org homeserver (and some
others) regarding authenticated access to inlined content
(https://matrix.org/blog/2024/06/26/sunsetting-unauthenticated-media/).

This change has basically broken nheko 0.11.  According to the github ticket, it's fixed in
nheko 0.12.0.

Is there any chance of either bumping the version number in bookworm, or backporting the
authentication change to 0.11?

Dear Maintainer,
I can confirm I am having the same issue. I cannot load ANY images on Nheko
with this version. It does not matter which homeserver I am communicating
with. In order for Nheko to still be usable on Debian Bookworm, there will
either have to be a bug fix or the 0.12 release of Nheko should be pushed to
Bookworm.
Thanks for your help and consideration.

I believe this bug is linked with a low level Matrix protocol change,
which also affected the python weechat plugin.

If so, then this commit in the nheko dependency "mtxclient" should fix it:

	Implement MSC3916 (auth for media)
https://github.com/Nheko-Reborn/mtxclient/commit/a70753812e3fb832df12b24ee0ee6c70d68060d5

- Chris

I gave it a test, and while the patch from the commit did not apply
cleanly to bookworm's version of nheko, what did apply fixed my issue
with image downloads.

I've attached the patch I tested.

- Chris

I had a problem of matrix.org images not showing which was fixed by upgrading
my matrix server (matrix-synapse) to the version in Unstable.  The problem I
found affected Nheko and Schildichat on Android.

While it might have been possible to address this with a patch to Nheko and it
would be ideal to have Nheko work with all combinations of servers, upgrading
to a recent version of matrix-synapse is a good option.

What version of nheko are you running in this case?  If you're
running sid's or even trixie's nheko, it is built with mtxclient 0.10.0
or higher, so your client was probably newer than your server,
in which case your fix would be correct.

Debian Bookworm still needs the patch to work with recent matrix servers.

- Chris

I think in this case it was Nheko from Unstable just before the release of
Trixie.  There were also problems with Schildichat in the same situation.

One would hope that a newer client could just fall back to the protocols used
by the older server.  But it seemed more complex in that images sent between
multiple older servers worked fine.

That would be nice, but with the way Matrix seems to be changing in recent
times users are probably better off just running Trixie for Matrix servers
that are used in a federated way.  It's still early days for Matrix support
and we don't even have a command-line Matrix client packaged yet (which is
something I plan to work on).

For servers, I would definitely agree that they run Trixie/Sid.  But
for nheko, I think applying the patch in Bookworm would let Matrix
users who simply have a matrix.org account have a working client again.

Excellent.

- Chris