Missing right-hand side of space boxes

[Stefan Monnier]

So I reverted my header-line to a non-3d look for SES's sake, but it's still
not shown correctly.  This time, there is no box-within-a-box (and no
header-line either):

   src/emacs -bg grey80 -q --eval "(progn (fundamental-mode) (apply 'insert 
(list \"hello \" (propertize (concat \"there\" (propertize \".\" 'display 
'(space :width 20))) 'face '(:box (:line-width 2 :style released-button))) \" 
there\")))"

it seems the problem is that the right-hand side of a box is not drawn if it
is a "space" display property (I haven't tried with images).


        Stefan