Dendrite cannot load conduit media

[matrixbot]

This issue was originally created by @ShadowJonathan at https://github.com/matrix-org/dendrite/issues/1997.

Background information

• Dendrite version or git SHA: 221ed52
• Monolith or Polylith?: Monolith
• SQLite3 or Postgres?: Postgres
• Running in Docker?: No
• go version: Go 1.17

Homeserver in question is jp.cube64128.xyz

These same symptoms are present on dendrite.matrix.org

Description

Dendrite fails without a proper error (also see https://github.com/matrix-org/dendrite/issues/1994) when loading some media from a Conduit server.

The following MXC from conduit.rs loads correctly on matrix.org and any other synapse server, but fails to load on dendrite;

mxc://conduit.rs/E649aeQG37N7VGvioBB5lrlVzt8VgPud

Synapse

`https://matrix.org/_matrix/media/r0/download/conduit.rs/E649aeQG37N7VGvioBB5lrlVzt8VgPud` `https://matrix.jboi.nl/_matrix/media/r0/download/conduit.rs/E649aeQG37N7VGvioBB5lrlVzt8VgPud`

Dendrite

`https://jp.cube64128.xyz/_matrix/media/r0/download/conduit.rs/E649aeQG37N7VGvioBB5lrlVzt8VgPud` `https://dendrite.matrix.org/_matrix/media/r0/download/conduit.rs/E649aeQG37N7VGvioBB5lrlVzt8VgPud`

Conduit

`https://conduit.koesters.xyz/_matrix/media/r0/download/conduit.rs/E649aeQG37N7VGvioBB5lrlVzt8VgPud` `https://beta.automatia.nl/_matrix/media/r0/download/conduit.rs/E649aeQG37N7VGvioBB5lrlVzt8VgPud`

No logs, but seeing as how this occurs on dendrite.matrix.org, this should be easy to trace.

If there are any details on what conduit could be doing wrong here, please close this issue with it and ping @timokoesters with the details

[matrixbot]

This comment was originally posted by @database64128 at https://github.com/matrix-org/dendrite/issues/1997#issuecomment-908253290.

My dendrite instance was built on commit 221ed52 from #1993 with Go 1.17.

• Monolith or Polylith?: Monolith
• SQLite3 or Postgres?: Postgres
• Running in Docker?: No

[matrixbot]

This comment was originally posted by @ShadowJonathan at https://github.com/matrix-org/dendrite/issues/1997#issuecomment-908255991.

I think that the EOF fallthrough here (as noted here)shadows an actual request error;

https://github.com/matrix-org/dendrite/blob/802f1c96f804f7a146e4e12e25b20c980a6af870/mediaapi/fileutils/fileutils.go#L133