bug#20727: 24.5; Font fallback doesn't work for the Emoji range

[Eli Zaretskii]

> Date: Sat, 13 Jun 2015 12:12:48 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: v.schneidermann@gmail.com, andrewjmoreton@gmail.com, 20727@debbugs.gnu.org
> 
> > Date: Fri, 12 Jun 2015 13:57:26 -0700
> > From: Paul Eggert <eggert@cs.ucla.edu>
> > CC: Eli Zaretskii <eliz@gnu.org>, 
> >  Vasilij Schneidermann <v.schneidermann@gmail.com>,
> >  Andy Moreton <andrewjmoreton@gmail.com>
> > 
> > src/emacs -Q -font 
> > -misc-fixed-medium-r-semicondensed--0-0-75-75-c-0-iso8859-1
> > 
> > and then by typing:
> > 
> > abc C-x 8 [ def C-x 8 ] ghi
> > 
> > This inserts "abc‘def’ghi" into *scratch*.  The display looks like "abc  
> > ‘def’  ghi" with huge spaces around the quotes (see attached 
> > screenshot).  There are similar problems with many other characters.  
> > Apparently this is because I don't have the Symbola font installed, so 
> > the change caused Emacs to fall back on Chinese double-width quotes 
> > rather than on the font it used before (which is -misc-liberation 
> > serif-medium-r-normal--13-94-100-100-p-74-iso10646-1 for the above 
> > invocation of Emacs).
> 
> Please tell the exact spec of the font with Chinese double-width
> quotes Emacs selected on that system (like you show above for the
> Liberation Serif font).  Also, please send (as an attachment) the
> entire contents of the *Help* buffer produced by "M-x describe-fontset
> RET RET" on that system.  I'd like to see what can be done to avoid
> that, even if Symbola is not installed.

Please also see if the latest master fixes the problem for you; if it
does, then you don't need to send all of the information I requested.
(I think I figured out why the original change caused Emacs to choose
a different font than what it would chose before that change.)