Boxes not boxed in the header-line

[Stefan Monnier]

I just noticed this inelegant behavior: in the header-line, when two
pieces of text have different box settings (but they're both 3d boxes), the
top and bottom part of the two texts are correctly drawn (with their
respective 3D effect), but there is not vertical line between the two to
mark the transition from one to the other.

E.g. compre the header-lines of

   emacs -Q foo.ses
vs
   emacs -Q --eval "(custom-set-faces '(header-line ((t :inherit mode-line))))" 
foo.ses

actually, even on "emacs -Q foo.ses", only the left separator line of boxes
are drawn, it seems.


        Stefan