Daniel van Vugt b1df6d08a5 backend-x11: Reintroduce XInitThreads
It was removed in 3.34 as part of 6ed5d2e2. And we thought that was the
only thread that might exist and use X11. But the top gnome-shell crasher
in 3.36 seems to suggest otherwise.

We don't know what or where the offending thread is, but since:

 1. We used XInitThreads for years already prior to 3.34; and

 2. Extensions or any change to mutter/gnome-shell could conceivably use
    threads to make X calls, directly or indirectly,

it's probably a good idea to reintroduce XInitThreads. The failing assertion
in libx11 is also accompanied by a strong hint:

```
fprintf(stderr, "[xcb] Most likely this is a multi-threaded client " \
                "and XInitThreads has not been called\n");
```

https://bugs.launchpad.net/bugs/1877075

Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/1252

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1256

(cherry picked from commit 1d5f9b6917517d6e777a652cfa5e648794dc632a)
2020-05-15 12:49:12 +02:00
..
2018-07-24 13:16:36 +00:00