[Bug 48269] New: Tray icon (XEMBED) moves when (0,0) coordinate is outside of the drawing area

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=48269

Bug ID: 48269
           Summary: Tray icon (XEMBED) moves when (0,0) coordinate is
                    outside of the drawing area
           Product: Wine
           Version: 4.21
          Hardware: x86
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: user32
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Created attachment 65934
  --> https://bugs.winehq.org/attachment.cgi?id=65934
Monitor layouts

For some uncommon monitor layouts wine tray icon is not working correctly.

When XEMBED is used X11 window should never move, because it is managed by the
system tray. KDE positions all tray icons in (0,0) position and renders them
off-screen (XComposite + XDamage). When screens are configured in a way, that
(0,0) is not is the first screen (?) area (attachment), wine icon tray window
tries to move itself. This repeats, window is moved further and further with
each event (not sure how it is triggered).

For example, primary screen has size 1440x900, second screen 900x1600 (vertical
position) and is positioned right of the primary screen, bottoms aligned. Check
attached picture for reference (second "NOT OK" example). It this scenario
(0,0) is 700 px above the primary screen (1600 - 900 = 700). Wine will move
tray icon to the position (0, 700). This should not happen, because tray icon
window is embedded, so it is managed by parent window.

I *suspect* the move is performed "UpdateLayeredWindowIndirect" in
dlls/user32/win.c. It calls set_window_pos which then moves the window using
X11 functions. I'm not that familiar with X11 to trace it correctly.

I tested mainly with wine-4.21 (Staging), but it also reproducible with old
wine 3.6.

Originally reported on KDE bug tracker:
https://bugs.kde.org/show_bug.cgi?id=414667