Header line and align-to.

[Matt Hodges]

In GNU Emacs 22.0.50.18 (i686-pc-linux-gnu, GTK+ Version 2.8.9)
 of 2006-08-13 on dugong
X server distributor `The X.Org Foundation', version 11.0.60802000
configured using `configure '--with-gtk''

With:

    (setq header-line-format "foo")

the header line (face) extends over the total width of the window
including fringes.

With either:

    (setq header-line-format
          (concat (propertize " " 'display `(space :align-to (+ left-fringe 
10))) "foo"))

or:

    (setq header-line-format
          (concat (propertize " " 'display `(space :align-to (+ left-margin 
10))) "foo"))

the header line starts after the left fringe (and a redisplay is
needed to clear the header-line region above the left fringe).

With:

    (set-window-margins nil 5 5)

the alignments work the same, but the header line starts after the
left margin; it does, however, extend above the right margin.

Is it intended that in the above cases the header line doesn't appear
across the whole window?

Thanks,

Matt