xprop zombie processes

[ces42]

Describe the bug
This extension does not reap the xprop processes used to remove decorations from maximized or tiled window.

To Reproduce
Steps to reproduce the behavior:

1. Set the "Hide window titlebars" to "maximixed".
2. Maximized and unmaximize a window a couple of times
3. Check htop for xprop zombie processes

Expected behavior
The extension should ensure that xprop processes are reaped

Environment (please complete the following information):

• OS: Ubuntu 22.10
• GNOME Shell 43.1
• Unite 70

Additional context
The xprop process is started in

unite-shell/[email protected]/window.js

Line 41 in eb8bdd3

Util.spawn(['xprop', '-id', xid, '-f', hint, '32c', '-set', hint, value])

and it turns out that gnome's Util.spawn adds the DO_NOT_REAP_CHILD flag when starting a process (see here). Further down in that function an exit handler is attached for the process, which I think is supposed to take care of reaping the child? But maybe what's happening is that the xprop process finishes before the handler is attached?

A possible fix here might be to just directly call

GLib.spawn_async(null,
                 ['xprop', '-id', xid, '-f', hint, '32c', '-set', hint, value],
                 null,
                 GLib.SpawnFlags.SEARCH_PATH,
                 () => {
                    try {
                        global.context.restore_rlimit_nofile();
                    } catch (err) {
                    }
                 }
    )