🚀 go-pugleaf

>This seems to work, but I'm not really happy about it as long as I do
>not understand why. So why do the functions above return values, that
>signalize the window is visible at it's GetRect()-area?

It was correct, that I was not happy about the ''solution' I used.
This test
  win_info.dwStyle&WS_VISIBLE)!<=0 && (win_info.dwStyle&WS_POPUP)==0
instead of 
  win_info.dwStyle&WS_VISIBLE)!<=0
excluded some other windows too from being checked and so some
overlappings weren't recognized.

My even worse, but functioning solution was to exclude this 'Myapp'
-window explicitely with
  char title[100];
  GetWindowText(hwnd, title, sizeof(title));
  if(strcmp(title, "Myapp")==0)
    goto overlap_check_passed;

~~~~~~~~~~~~~~~~~~

There are two main-issues I do not understand:

(1) Where does this Myapp-window comes from. It is none of the forms I
created with BDS2006 (VCL)?

(2) Why does the IsWindowVisible()-function delivers true, but  is not
visible at it's GetWindowRect()-posiitions; it just appears in the
task-bar.

Thanks,

Michael