Sometimes, e.g. when xdg-open has to start the browser, the xdg-open
process can stay around until the browser exits, which freezes the
client. Instead, we should not wait for xdg-open to exit.
However, we can't simply not call wait, as that would leave the
xdg-open process around as a zombie. We could turn off the SIGCHLD
handler, but that's a global solution to a local problem. Instead, we
call setsid and fork again to detach the xdg-open process as if it's a
daemon, and let init take care of the reaping process.
Co-Authored-By: Tudor Brindus <me@tbrindus.ca>
This is currently only implemented for Linux.
On Windows, ShellExecute should be used, but that should be done when it's
actually needed so it could be tested.
