bug#3586: Invalid face height

[Stefan Monnier]

> Debugger entered--Lisp error: (error "Invalid face height" 0.0)
[...]
>   custom-declare-face(tabbar-default (((... ...) :inherit variable-pitch 
> :height 0.0 :foreground "grey75" :background "gray50") ((... ...) :inherit 
> variable-pitch :height 0.0 :foreground "black" :background "white") ((... 
> ...) :inherit variable-pitch :height 0.0 :foreground "white" :background 
> "black") (t :inherit variable-pitch :height 0.0 :foreground "gray50" 
> :background "gray75")) "Default face used in the tab bar." :group tabbar)

Why is this face defined to have a height of 0.0?
This looks really odd (I'm not surprised Emacs signals it as an invalid
face height, although it might also be OK to change Emacs to accept such
values).


        Stefan