bug#34138: 27.0.50; Delayed display of PDF file images

[martin rudalics]

>> It seems that 'doc-view-new-window-function' fails in some way.  This
>> time I have to CC Tassilo.  Maybe he has a clue.
>
> No, sorry, not really.  I've tried reproducing Stephen's issue both with
> -Q (using doc-view) and with my configuration (which also uses
> pdf-view-mode).  But for me the greeting text and then the image of the
> first page for doc-view or the image of the first page for pdf-view-mode
> are displayed without any delay.
>
> I'm running the current master, 5961e4fa42.

Strange because Andreas said that he can reproduce it as well.  I'm
afraid we have to wait for further people to kick in to get a common
pattern of why this can fail.  To me this looks like a race condition
where with the old window configuration change convention the image
producing system was reliably incapable of providing the image at the
time the hook was run while with the new convention the image may have
been already produced at the time the hook is run.

martin