bug#2334: 23.0.90; emacs-snapshot has ugly fonts when using set-default-font elisp function

[Kenichi Handa]

In article <8763jaqu7b.fsf@cyd.mit.edu>, Chong Yidong <cyd@stupidchicken.com> 
writes:

> "Theodore Ts'o" <tytso@mit.edu> wrote:
> > Using emacs-snapshot-20090207, the text display becomes very ugly when
> > set via:
> > (set-default-font "DejaVu Sans Mono-10")
> > However, if the font is set via the menu bar: Options->Set Default Font
> > then the fonts look good (i.e., with proper anti-aliasing).

> Hi Handa-san,

> I think we should give the xft font backend (where it is available) a
> higher priority than the x backend; otherwise, users will keep
> experiencing bugs like this.

I at first want to figure out why the above two methods for
seting a font are different.  At least, I can't reproduce
the difference.  Can you?  When I have "dejavu sans mono"
fonts both for fontconfig and X as below, both methods set
the default font to X font.

% fc-list 'dejavu sans mono'
DejaVu Sans Mono:style=Bold Oblique
DejaVu Sans Mono:style=Oblique
DejaVu Sans Mono:style=Book
DejaVu Sans Mono:style=Bold
% xlsfonts '*-dejavu sans mono-*'
-dejavu-dejavu sans mono-bold-o-normal--0-0-0-0-c-0-iso10646-1
-dejavu-dejavu sans mono-bold-o-normal--0-0-0-0-m-0-iso10646-1
-dejavu-dejavu sans mono-bold-r-normal--0-0-0-0-c-0-iso10646-1
-dejavu-dejavu sans mono-bold-r-normal--0-0-0-0-m-0-iso10646-1
-dejavu-dejavu sans mono-medium-o-normal--0-0-0-0-c-0-iso10646-1
-dejavu-dejavu sans mono-medium-o-normal--0-0-0-0-m-0-iso10646-1
-dejavu-dejavu sans mono-medium-r-normal--0-0-0-0-c-0-iso10646-1
-dejavu-dejavu sans mono-medium-r-normal--0-0-0-0-m-0-iso10646-1
[...]

---
Kenichi Handa
handa@m17n.org