maintainer-feedback requested: [Bug 253277] x11/xtrans: Don't unlink existing UNIX sockets => allows multiple X sessions from sddm

[bugzilla-noreply at freebsd.org]

Bugzilla Automation <bugzilla at FreeBSD.org> has asked freebsd-x11 (Nobody)
<x11 at FreeBSD.org> for maintainer-feedback:
Bug 253277: x11/xtrans: Don't unlink existing UNIX sockets => allows multiple X
sessions from sddm
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=253277



--- Description ---
Patch that removes the `unlink` call before binding some UNIX socket.

The problem with the existing approach is that, when Xorg is launched as
`root`, it can always unlink existing sockets, which it does when no display is
explicitly specified and `-displayfd` is used.

Moreover, the X server removes the UNIX socket when exiting (even in most
abnormal cases).

Typically, sddm exactly triggers the problem. So when you try to open another
session through it, the first session's sockets are crushed and it becomes
stale.

I'm proposing the patch here since it is not practically useful on platforms
that launch Xorg with an unprivileged user and because upstream seems inactive.