This is a follow-up to bug #220090. Avoiding child setup functions is desirable because it could allow GSubprocess to use posix_spawn() instead of fork() in the future. That's not possible to do if we have code that needs to run between fork() and exec().
In this case, the child setup is used only to unset CLOEXEC. We could simply not set it in the first place. This only fails if a secondary thread decides to launch a subprocess before XDGDBusProxyLauncher::launch returns. That window already exists in many other places (e.g. anywhere else setCloseOnExec is called, such as for IPC::Connection objects). Threads should not do that.
This also fixes a bug where unsetting CLOEXEC would fail if we get unlucky and receive EINTR. A loop is required here. WTF::setCloseOnExec handles that for us.
Created attachment 420666 [details]
Created attachment 420667 [details]
Committed r273087: <https://commits.webkit.org/r273087>
All reviewed patches have been landed. Closing bug and clearing flags on attachment 420667 [details].