Sharing multiple images from external app doesn't apply the correct mime tag

[bblacher]

Steps to reproduce

1. Use some external app (in my case LineageOS gallery)
2. Select and share multiple images using Element X
3. Observe those images not getting bridged using mautrix-signal with an error stating ⚠️ Your message was not bridged: unsupported media type (image/* in m.image)

Outcome

What did you expect?

The images should get bridged

What happened instead?

The images didn't get bridged because Element X seems to apply the wrong mime tags

Your phone model

Google Pixel 8 Pro

Operating system version

CalyxOS 6.4.0 (Android 15)

Application version and app store

Element X 2025.02 from F-Droid

Homeserver

Synapse v1.124.0

Will you send logs?

No

Are you willing to provide a PR?

No

Additional Information

I reported this issue to mautrix-signal at first, see mautrix/signal#587 but it seems like this is a bug with Element X. I also tried sharing from Aves (alternative gallery app) and got the same result. If this is an issue with LineageOS gallery AND Aves please close this issue and I will report it at the respective repos. Thanks!

[szimszon]

Same here with Nothing Gallery ....

[szimszon]

ElementX: 25.03.0 (202503002) from F-Droid

[retarepo]

I guess it's the same problem as #3848, for me it occurs with single images as well, if they are shared from another app (e.g. Jerboa). Currently this issue is blocking me from switching from legacy Element.

[anytimesoon]

I get the same issue. It happens when sharing directly from an app. This issue is not present in legacy element, like retarepo said.

[jmartinesp]

I was finally able to reproduce this. It seems like we take the mime type from the intent sent to our app instead of the files shared, so if you selected i.e. a png and a jpg file, instead of image/jpeg or image/png mime types we receive image/* since the actual type is mixed.

The fix would be to retrieve the mime type from the files themselves.