bug#23362: 25.0.93; Unicode chars (such as 0x1F600) are not rendered correctly

[Eli Zaretskii <eliz@gnu.org>]

> From: Peter Wang <ptr.wang@gmail.com>
> Date: Mon, 25 Apr 2016 01:40:59 +0800
> 
> On OSX, this pretest release breaks render of some unicode chars.
> 
> ;;; 😀😂
> (set-frame-font "Monaco:pixelsize=16")
> (set-fontset-font
> (frame-parameter nil 'font)
> 'symbol (font-spec :family "Apple Color Emoji") nil 'prepend)
> 
> there should be two symbols in the first line of above snippets if
> rendered correctly.
> 
> BTW, the last pretest does not have such issue. the version of last
> pretest is:
> 
> GNU Emacs 25.0.92.1 (x86_64-apple-darwin13.4.0, NS appkit-1265.21 Version 10.9.5 (Build 13F1603)) of
> 2016-03-03

Isn't this a consequence of this commit:

  commit 9344612d3cd164317170b6189ec43175757e4231
  Author: YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp>
  Date:   Tue Apr 12 08:26:51 2016 +0900

      Disable multicolor fonts on OS X since they are not supported on free system

      * src/macfont.m (macfont_list): Don't use color bitmap fonts.

If you revert it, does the problem go away?  If not, can you please
bisect the emacs-25 branch between 25.0.92 and now, and see which
commit caused this?

Thanks.