Async/Sync url-copy-file?

[Lennart Borgman]

Can a sane person please explain to me how this code

    (message "before url-copy-file %S" temp-list-file)
    (url-copy-file url temp-list-file t t)) ;; overwrite, keep time
    (message "after  url-copy-file %S" temp-list-file)
    (with-current-buffer (find-file-noselect temp-list-file)
      (set-visited-file-name nil t)
      (message "before (delete-file %S)" temp-list-file)
      (when (file-exists-p temp-list-file) (delete-file temp-list-file))
      (message "after  (delete-file %S)" temp-list-file)

could give this output:

    before url-copy-file "c:/test/d27/web-vcs-temp-list.tmp"
    before (delete-file "c:/test/d27/web-vcs-temp-list.tmp")
    after  (delete-file "c:/test/d27/web-vcs-temp-list.tmp")
    before url-copy-file "c:/test/d27/util/web-vcs-temp-list.tmp"
    Contacting host: bazaar.launchpad.net:80
    Wrote c:/test/d27/util/web-vcs-temp-list.tmp
    after  url-copy-file "c:/test/d27/util/web-vcs-temp-list.tmp"

And why I am asked if I want to revert the buffer when temp-list-file
changes on disk?

Could this be a bug in the url-copy-file so that it runs async?