Comment 11 for bug 1921931

(In reply to Martin Stránský [:stransky] from comment #3)
> I don't think we should enable mixing X11/DBus remote
I agree.

> launcher for Firefox on Wayland which can be registered as a default launcher for html links
Yes, a custom launcher with GDK_BACKEND=wayland override can be created in ~/.local/share/applications/ and registered using "xdg-settings set default-web-browser custom-launcher.desktop". It would cause the other desktop applications to open the links using the correct version of Firefox.

However, even after creating such a launcher and registering it, Firefox would _not_ detect that it is in fact the default browser and it would offer the user to set it as the default browser. If the user agrees, Firefox would create a new launcher with a name similar to "userapp-Nightly-8YETTZ.desktop" and register it. That launcher, however, would use the Firefox executable _directly_, i.e. without the GDK_BACKEND=wayland override.

That would result in launching the non-Wayland version of Firefox by other desktop applications by default, which would then cause the behavior mentioned in this issue.

I think that one of the ways to resolve this would be to update the process of setting the default browser, so that the created launcher would contain the GDK_BACKEND=wayland override if the Firefox process that creates it also runs on Wayland.