martin rudalics <rudalics@gmx.at> writes:

>> Is that OK to call a cl-lib function in the second patch even 
>> if this library is not required in window.el ?
>
> No.  I only re-compiled and did not build.  Please try to avoid 
> it since
> otherwise we get a
>
> In end of data:
> ../../lisp/window.el:5039:29: Warning: the function 
> ‘cl-find-if-not’ is not
>     known to be defined.
>
> warning.

Here an alternative version using subr.el instead :