server: Treat desktop as a top-level window.

dlls/user32/tests/msg.c

@@ -9250,7 +9250,7 @@ static void test_SetForegroundWindow(void)
     trace("SetForegroundWindow( GetDesktopWindow() )\n");
     SetForegroundWindow( GetDesktopWindow() );
     ok_sequence(SetForegroundWindowSeq, "SetForegroundWindow( desktop ) away from "
-                                        "foreground top level window", TRUE);
+                                        "foreground top level window", FALSE);
     trace("done\n");
 
     DestroyWindow(hwnd);

dlls/user32/tests/win.c

@@ -2213,12 +2213,9 @@ static void test_SetForegroundWindow(HWND hwnd)
 
     hwnd2 = GetForegroundWindow();
     ok(hwnd2 == hwnd, "Wrong foreground window %p\n", hwnd2);
-    todo_wine
-    {
     ok(SetForegroundWindow( GetDesktopWindow() ), "SetForegroundWindow(desktop) error: %d\n", GetLastError());
     hwnd2 = GetForegroundWindow();
     ok(hwnd2 != hwnd, "Wrong foreground window %p\n", hwnd2);
-    }
 
     ShowWindow(hwnd, SW_HIDE);
     check_wnd_state(0, 0, 0, 0);

server/window.c

@@ -514,7 +514,7 @@ int is_child_window( user_handle_t parent, user_handle_t child )
 int is_top_level_window( user_handle_t window )
 {
     struct window *win = get_user_object( window, USER_WINDOW );
-    return (win && win->parent && is_desktop_window(win->parent));
+    return (win && (is_desktop_window(win) || is_desktop_window(win->parent)));
 }
 
 /* make a window active if possible */