Created attachment 765672 [details]
screenshot

STR:

1. Install torbrowser-launcher and run the Tor Browser
2. Go to about:preferences and set it as default browser
3. Click to open an HTTP link from another application (tested with claws-mail
and newsbeuter)

EXPECTED
The link should open in Tor Browser

ACTUAL
The link opens in Chromium (the previous default browser). Also
chrome://settings/defaultBrowser still shows that "Chromium is your default
browser" regardless of:

[~]: cat .config/mimeapps.list | grep browser
x-scheme-handler/http=exo-web-browser.desktop
x-scheme-handler/https=exo-web-browser.desktop
x-scheme-handler/http=exo-web-browser.desktop

As seen on the screenshot both browsers claim to be default simultaneously.