bug#14062: 24.3.50; emacs_backtrace.txt

[martin rudalics]

> Sorry, I was actually talking about something else entirely: about
> this:
>
>    + !NILP (BVAR (XBUFFER ((W)->contents), mode_line_format))
>
> As for FRAME_WANTS_MODELINE_P, it's zero for minibuffer frames and
> tooltip frames.  Are you saying that these frames should be able to
> have header lines?

No.  As far as minibuffer frames are concerned, these should be excluded
by the !MINI_WINDOW_P ((W)) conjunct since make_minibuffer_frame sets
XWINDOW (mini_window)->mini = 1.  I forgot about tooltip windows though.

Note that frame.h has this

  /* 0 means, if this frame has just one window,
     show no modeline for that window.  */
  unsigned wants_modeline : 1;

and we set this to 0 in make_minibuffer_frame but we don't set this for
tooltip frames - that's why I didn't find it in the first place.
Moreover, the comment insinuates that when the frame has two windows we
might want to show a modeline so WINDOW_WANTS_MODELINE_P would have to
check that (I doubt that such frames exist in practice though).

Finally, frame.h also has this comment

/* Not really implemented.  */
#define FRAME_WANTS_MODELINE_P(f) (f)->wants_modeline

which only adds to my confusion.

martin