linux: Fix process PID to window mapping for X11

[0xtimsb]

Closes #22326

This PR adds process PID information to window created by X11, so that window manager can identify which process this window belongs to. Without this property, the window manager would have no reliable way to know which process created this window.

In original issue, robotgo throws error on x, y, w, h := robotgo.GetBounds(pid) this method. If we go deeper into the source code of robotgo, it calls GetXidFromPid which goes through all windows, and tries to check for provided pid. Hence, when it tries to do that for Zed, it fails and returns 0, err to caller.

// Robotgo source code trying to look through all windows and query pid

// GetXidFromPid get the xid from pid
func GetXidFromPid(xu *xgbutil.XUtil, pid int) (xproto.Window, error) {
	windows, err := ewmh.ClientListGet(xu)
	if err != nil {
		return 0, err
	}

	for _, window := range windows {
		wmPid, err := ewmh.WmPidGet(xu, window)
		if err != nil {
			return 0, err
		}

		if uint(pid) == wmPid {
			return window, nil
		}
	}

	return 0, errors.New("failed to find a window with a matching pid.")
}

Querying for pid for active Zed window:

Before:

tims@lemon ~/w/go-repro [127]> xprop -root _NET_ACTIVE_WINDOW
_NET_ACTIVE_WINDOW(WINDOW): window id # 0x4e00002
tims@lemon ~/w/go-repro> xprop -id 0x4e00002 _NET_WM_PID
_NET_WM_PID:  not found.

After:

tims@lemon ~/w/go-repro> xprop -root _NET_ACTIVE_WINDOW
_NET_ACTIVE_WINDOW(WINDOW): window id # 0x4e00002
tims@lemon ~/w/go-repro> xprop -id 0x4e00002 _NET_WM_PID
_NET_WM_PID(CARDINAL) = 103548
tims@lemon ~/w/go-repro>

Correct zed process PID (below) assosiated with zed window (shown above):

Release Notes:

• Fix robotgo failing when Zed window is open on Linux