bug#3602: 23.0.94; window-line-height problems

[martin rudalics]

>> That seems to say that if you have a header line, then you can get its
>> height in pixels this way (window-line-height 'header-line), and
>> similarly for mode-line. But that doesn't seem to work.
>
> (window-line-height 'mode-line)
> => nil
>
> So I can confirm this bug.

The doc-string of `window-line-height' says ...

     Return nil if window display is not up-to-date.  In that case, use
    `pos-visible-in-window-p' to obtain the information.

... and the Elisp manual says ...

     If the display is not up to date, `window-line-height' returns
     `nil'.  In that case, `pos-visible-in-window-p' may be used to
     obtain related information.

... so I wonder how you can "confirm this bug" ;-)

martin