winex11.drv: Set the WM_STATE_ABOVE hint on topmost windows.

dlls/winex11.drv/winpos.c

@@ -181,6 +181,7 @@ static void update_wm_states( Display *display, struct x11drv_win_data *data, BO
     static const unsigned int state_atoms[NB_WM_STATES] =
     {
         XATOM__NET_WM_STATE_FULLSCREEN,
+        XATOM__NET_WM_STATE_ABOVE,
         XATOM__NET_WM_STATE_SKIP_PAGER,
         XATOM__NET_WM_STATE_SKIP_TASKBAR
     };
@@ -195,6 +196,8 @@ static void update_wm_states( Display *display, struct x11drv_win_data *data, BO
         new_state |= (1 << WM_STATE_FULLSCREEN);
 
     ex_style = GetWindowLongW( data->hwnd, GWL_EXSTYLE );
+    if (ex_style & WS_EX_TOPMOST)
+        new_state |= (1 << WM_STATE_ABOVE);
     if (ex_style & WS_EX_TOOLWINDOW)
         new_state |= (1 << WM_STATE_SKIP_TASKBAR) | (1 << WM_STATE_SKIP_PAGER);
 

dlls/winex11.drv/x11drv.h

@@ -578,6 +578,7 @@ enum x11drv_atoms
     XATOM__NET_WM_PID,
     XATOM__NET_WM_PING,
     XATOM__NET_WM_STATE,
+    XATOM__NET_WM_STATE_ABOVE,
     XATOM__NET_WM_STATE_FULLSCREEN,
     XATOM__NET_WM_STATE_SKIP_PAGER,
     XATOM__NET_WM_STATE_SKIP_TASKBAR,
@@ -649,6 +650,7 @@ enum x11drv_window_messages
 enum x11drv_wm_state
 {
     WM_STATE_FULLSCREEN,
+    WM_STATE_ABOVE,
     WM_STATE_SKIP_PAGER,
     WM_STATE_SKIP_TASKBAR,
     NB_WM_STATES

dlls/winex11.drv/x11drv_main.c

@@ -135,6 +135,7 @@ static const char * const atom_names[NB_XATOMS - FIRST_XATOM] =
     "_NET_WM_PID",
     "_NET_WM_PING",
     "_NET_WM_STATE",
+    "_NET_WM_STATE_ABOVE",
     "_NET_WM_STATE_FULLSCREEN",
     "_NET_WM_STATE_SKIP_PAGER",
     "_NET_WM_STATE_SKIP_TASKBAR",