bug#22609: 24.5; Different Font display for windows32 implementation

[Andy Moreton <andrewjmoreton@gmail.com>]

On Tue 09 Feb 2016, Matthew Fidler wrote:

> Under windows32 individual glyphs from a font are not displayed in the mode
> line (or the header-line).
>
> How to reproduce:
>
> Download github-octicons (https://octicons.github.com/)
>
> Evaluate the following
>
> (defvar mode-icons-octicons-font
>   (find-font (font-spec :name "github-octicons")))
>
> (setq test (propertize "test" 'display (make-string 1 #xf0c9) 'font
> 'mode-icons-octicons-font))

That codepoint is in the private-use area of Unicode, so I woud not
expct it to work (however I am far from expert in this area). You may need to
add the font to a fontset for the needed range of codepoints.

For example, adding this to default fontset shows the desired character
in the header line:

(set-fontset-font t '(#xf000 . #xf0e7) (font-spec :name "github-octicons"))

    AndyM