From 11c2b815c97e919ddcf133afa61154b0a48e16cd Mon Sep 17 00:00:00 2001
From: Po Lu <luangruo@yahoo.com>
Date: Tue, 11 Jun 2024 16:59:15 +0800
Subject: [PATCH] Enable support for color fonts in recent releases of Xft

* etc/PROBLEMS (Some fonts are detected..): Document that Xft
2.3.6 should have resolved this issue.

* src/ftfont.c (ftfont_spec_pattern, ftfont_list): Disable
inhibition of color fonts on Xft 2.3.6 and subsequent versions.

(cherry picked from commit cc30758eed9488aed4149adbf7a285622c3ec446)
---
 etc/PROBLEMS |  2 ++
 src/ftfont.c | 27 ++++++++++++++++++++++-----
 2 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/etc/PROBLEMS b/etc/PROBLEMS
index 6c143d22de4..9cbcee51fe8 100644
--- a/etc/PROBLEMS
+++ b/etc/PROBLEMS
@@ -977,6 +977,8 @@ to take advantage of.
 
 ** Some fonts are detected but not usable under Xft.
 
+We understand that these issues were resolved in Xft release 2.3.6.
+
 Some fonts might not be usable under Emacs even though they show up in
 the font family list when Emacs is built with Xft.  This is because
 Emacs prevents fonts that have color glyphs (such as color Emoji) from
diff --git a/src/ftfont.c b/src/ftfont.c
index 214d7532d6f..c89feea1d46 100644
--- a/src/ftfont.c
+++ b/src/ftfont.c
@@ -658,6 +658,11 @@ ftfont_get_open_type_spec (Lisp_Object otf_spec)
 }
 
 #if defined HAVE_XFT && defined FC_COLOR
+#if (XFT_MAJOR < 2						\
+    || (XFT_MAJOR == 2 && (XFT_MINOR < 3			\
+			   || (XFT_MINOR == 3			\
+			       && XFT_REVISION < 6))))
+
 static bool
 xft_color_font_whitelisted_p (const char *family)
 {
@@ -675,7 +680,9 @@ xft_color_font_whitelisted_p (const char *family)
 
   return false;
 }
-#endif
+
+#endif /* Xft < 2.3.6 */
+#endif /* HAVE_XFT && FC_COLOR */
 
 static FcPattern *
 ftfont_spec_pattern (Lisp_Object spec, char *otlayout,
@@ -815,14 +822,19 @@ ftfont_spec_pattern (Lisp_Object spec, char *otlayout,
       && ! FcPatternAddBool (pattern, FC_SCALABLE, scalable ? FcTrue : FcFalse))
     goto err;
 #if defined HAVE_XFT && defined FC_COLOR
-  /* We really don't like color fonts, they cause Xft crashes.  See
-     Bug#30874.  */
+#if (XFT_MAJOR < 2						\
+     || (XFT_MAJOR == 2 && (XFT_MINOR < 3			\
+			    || (XFT_MINOR == 3			\
+				&& XFT_REVISION < 6))))
+  /* We really don't like color fonts, they cause Xft crashes with
+     releases older than 2.3.6.  See Bug#30874.  */
   if (xft_ignore_color_fonts
       && (NILP (AREF (spec, FONT_FAMILY_INDEX))
 	  || NILP (Vxft_color_font_whitelist))
       && ! FcPatternAddBool (pattern, FC_COLOR, FcFalse))
     goto err;
-#endif
+#endif /* Xft < 2.3.6 */
+#endif /* HAVE_XFT && FC_COLOR */
 
   goto finish;
 
@@ -959,6 +971,10 @@ ftfont_list (struct frame *f, Lisp_Object spec)
     {
       Lisp_Object entity;
 #if defined HAVE_XFT && defined FC_COLOR
+#if (XFT_MAJOR < 2						\
+     || (XFT_MAJOR == 2 && (XFT_MINOR < 3			\
+			    || (XFT_MINOR == 3			\
+				&& XFT_REVISION < 6))))
       {
         /* Some fonts, notably NotoColorEmoji, have an FC_COLOR value
            that's neither FcTrue nor FcFalse, which means FcFontList
@@ -975,7 +991,8 @@ ftfont_list (struct frame *f, Lisp_Object spec)
             == FcResultMatch && b != FcFalse)
             continue;
       }
-#endif
+#endif /* Xft < 2.3.6 */
+#endif /* HAVE_XFT && FC_COLOR */
       if (spacing >= 0)
 	{
 	  int this;
-- 
2.39.2