bug#72268: 31.0.50; Color emoji rendering

[Manuel Giraud via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

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Eli Zaretskii <eliz@gnu.org> writes:

[...]

> Indeed, we don't need to describe all the details there.  We just need
> to say that display of color Emoji needs the FreeType library with PNG
> support, and if such a FreeType library is not available, users could
> consider rebuilding it with PNG support on their system.

What do you think of this?

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From f2b542d9efdee4908e5a99a1a62adf610048b4b5 Mon Sep 17 00:00:00 2001
From: Manuel Giraud <manuel@ledu-giraud.fr>
Date: Thu, 25 Jul 2024 13:57:59 +0200
Subject: [PATCH] Document unsupported color Emoji on OpenBSD

Bug#72268

* etc/PROBLEMS (Runtime problems related to font handling):
Document unsupported color Emoji on OpenBSD.
---
 etc/PROBLEMS | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/etc/PROBLEMS b/etc/PROBLEMS
index f8fb9f90c0b..939005780a8 100644
--- a/etc/PROBLEMS
+++ b/etc/PROBLEMS
@@ -1274,6 +1274,27 @@ Emacs will select some other font instead.
 The only workaround is not to choose such font variants as the default
 font when running Emacs on MS-Windows.
 
+** On OpenBSD, color Emoji are not supported by default.
+
+The system's FreeType library is not built with libpng support, so it
+can't display color emoji.  This is due to the fact that, on OpenBSD,
+libpng is provided through ports and that a base component cannot depend
+on that.
+
+However, you can add support for PNG in the system's FreeType library by
+following those steps:
+	1. Install the 'png' package.
+	2. Read the release(8) man page for how to get Xenocara sources.
+	3. Patch the file
+	   "/usr/xenocara/lib/freetype/include/freetype/config/ftoption.h"
+	   by uncommenting the "#define FT_CONFIG_OPTION_USE_PNG" line.
+	4. Patch the file "/usr/xenocara/lib/freetype/Makefile" by
+	   appending "-L/usr/local/lib -lpng" to LDADD and appending
+	   "-I/usr/local/include" to CPPFLAGS.
+	5. Build and install Xenocara (also, see release(8)).
+
+Note that this support will be gone after each OpenBSD's system upgrade.
+
 * Internationalization problems
 
 ** M-{ does not work on a Spanish PC keyboard.
-- 
2.45.2


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-- 
Manuel Giraud