Give Slack access to system /tmp

[lobner]

We often use /tmp to store temporary files, of cause... but flatpak Slack does not give access to this.

It was also a problem (issue #11) with GIMP, which they solved here flathub/org.gimp.GIMP@bf7aff3 - could you possibly make the same correction?

[flathubbot]

Started test build 23380

[flathubbot]

Build 23380 failed

[flathubbot]

Started test build 23383

[flathubbot]

Build 23383 successful
To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/22460/com.slack.Slack.flatpakref

[egilkv]

Just voicing in my support for the feature. The default Gimp behaviour of playing games with /tmp breaks an important feature in my Ubuntu: Opening an image from the Firefox browser in the Image Viewer, and then from the viewer selecting Open With->GIMP. The browser image is stored in /tmp/mozilla_username0/something.jpg which Gimp cannot find.

[shaicoleman]

For security reasons, it's not a good idea to give access to /tmp by default.
If you need to access /tmp you can always configure it manually,
e.g. sudo flatpak override com.slack.Slack --filesystem=/tmp

[vchernin]

You can also edit a flatpak's permissions graphically with flatseal.

[johnnyapol]

electron/electron#19159 (which was merged and should be landing in electron 14) makes electron apps use the GtkFileChooserNative which means file uploads would go through the flatpak portal and therefore no overrides would be needed. Unfortunately, electron 14 isn't released yet (and it would take time for slack to upgrade to it), but this will resolve this issue at some point in the future

[WhyNotHugo]

I'm going to close this based on the security issues mentioned in comments above.

Electron has already fixed this via electron/electron#19159, once Slack updates their electron version to at least 14, picking any file will work natively.