bug#54038: 29.0.50; doc-view cannot show different pages in different tabs

[Juri Linkov]

>> The problem is that this doesn't create a new window
>> from the selected window:
>>
>>    (window-state-put (window-state-get (selected-window)) (selected-window))
>
> This should put the contents of the selected window into itself - a NOOP
> WOW.  What else did you expect?

Thanks, now this is simplified in master.