commit 408bf21a8c8b5bf5a78785608255463ad1038871
Author: Robert Pluim <rpluim@gmail.com>
Date:   Tue Apr 3 11:06:01 2018 +0200

    Ignore color fonts when using Xft
    
    * src/font.c (syms_of_font): New configuration variable
    xft-ignore-color-fonts, default t.
    * src/ftfont.c (ftfont_spec_pattern): Tell fontconfig to ignore
    color fonts if xft-ignore-color-fonts is t.  (Bug#30874, Bug#30045)
    * etc/NEWS: Document xft-ignore-color-fonts.

diff --git a/src/font.c b/src/font.c
index a6d3f5d479..ef3f92b594 100644
--- a/src/font.c
+++ b/src/font.c
@@ -5473,6 +5473,13 @@ Disabling compaction of font caches might enlarge the Emacs memory
 footprint in sessions that use lots of different fonts.  */);
   inhibit_compacting_font_caches = 0;
 
+  DEFVAR_BOOL ("xft-ignore-color-fonts",
+	       Vxft_ignore_color_fonts,
+	       doc: /*
+Non-nil means don't query fontconfig for color fonts, since they often
+cause Xft crashes.  Only has an effect in Xft builds.  */);
+  Vxft_ignore_color_fonts = 1;
+
 #ifdef HAVE_WINDOW_SYSTEM
 #ifdef HAVE_FREETYPE
   syms_of_ftfont ();
diff --git a/src/ftfont.c b/src/ftfont.c
index c2e093e633..24a92dd52e 100644
--- a/src/ftfont.c
+++ b/src/ftfont.c
@@ -764,6 +764,13 @@ ftfont_spec_pattern (Lisp_Object spec, char *otlayout, struct OpenTypeSpec **ots
   if (scalable >= 0
       && ! FcPatternAddBool (pattern, FC_SCALABLE, scalable ? FcTrue : FcFalse))
     goto err;
+#ifdef HAVE_XFT
+  /* We really don't like color fonts, they cause Xft crashes.  See
+     Bug#30874.  */
+  if (Vxft_ignore_color_fonts
+      && ! FcPatternAddBool(pattern, FC_COLOR, FcFalse))
+    goto err;
+#endif
 
   goto finish;