Add fonts from all XDG_DATA_DIRS, not just XDG_DATA_HOME.

See <http://bugs.gnu.org/41174>.
Author: Leo Prikler <leo.prikler@student.tugraz.at>
Index: webkitgtk-2.28.2/Source/WebKit/UIProcess/Launcher/glib/BubblewrapLauncher.cpp
===================================================================
--- a/Source/WebKit/UIProcess/Launcher/glib/BubblewrapLauncher.cpp
+++ b/Source/WebKit/UIProcess/Launcher/glib/BubblewrapLauncher.cpp
@@ -387,6 +387,7 @@ static void bindFonts(Vector<CString>& args)
     const char* homeDir = g_get_home_dir();
     const char* dataDir = g_get_user_data_dir();
     const char* cacheDir = g_get_user_cache_dir();
+    const char* const * dataDirs = g_get_system_data_dirs();

     // Configs can include custom dirs but then we have to parse them...
     GUniquePtr<char> fontConfig(g_build_filename(configDir, "fontconfig", nullptr));
@@ -403,6 +404,10 @@ static void bindFonts(Vector<CString>& args)
     bindIfExists(args, fontHomeConfigDir.get());
     bindIfExists(args, fontData.get());
     bindIfExists(args, fontHomeData.get());
+    for (auto dataDir = dataDirs; dataDir != nullptr && *dataDir != nullptr; dataDir++) {
+        GUniquePtr<char> fontDataDir(g_build_filename(*dataDir, "fonts", nullptr));
+        bindIfExists(args, fontDataDir.get());
+    }
     bindIfExists(args, "/var/cache/fontconfig"); // Used by Debian.
 }
diff/etc/openrc?id=7bbbe0338717505b362b60b0e44406769ae50c28'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/etc/openrc'>
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<div class='path'>path: <a href='/guix/log/?id=7bbbe0338717505b362b60b0e44406769ae50c28'>root</a>/<a href='/guix/log/etc?id=7bbbe0338717505b362b60b0e44406769ae50c28'>etc</a>/<a href='/guix/log/etc/openrc?id=7bbbe0338717505b362b60b0e44406769ae50c28'>openrc</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/etc/openrc?id=7bbbe0338717505b362b60b0e44406769ae50c28&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2021-07-07 23:54:20 -0400'>2021-07-07</span></td><td><a href='/guix/commit/etc/openrc?id=4cbe0127a668cbcc64087c5d311308b59d39b104'>guix-install.sh: Prompt for configuring substitutes discovery.</a><span class='msg-avail'>...<span class='msg-tooltip'>Also ensure prompt_yes_no always print the message with a trailing space,
which is more pleasing to the eye.

* etc/guix-daemon.conf.in &lt;--discover=no&gt;: New guix-daemon option.
* etc/guix-daemon.service.in: Likewise.
* etc/init.d/guix-daemon.in: Likewise.
* etc/openrc/guix-daemon.in: Likewise.
* etc/guix-install.sh (configure_substitute_discovery): New procedure.
(sys_enable_guix_daemon): Ask the user whether automatic substitute discovery
should be enabled.  Set the '--discover' argument accordingly.
(prompt_yes_no): Add a trailing space to the message.
(sys_authorize_build_farms): Remove trailing space from the message argument.
* NEWS (Distribution): Add news.
</span></span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2020-09-17 14:10:42 +0200'>2020-09-17</span></td><td><a href='/guix/commit/etc/openrc?id=cabac732deffafc796537658a6c33c6c4aec821e'>guix-install.sh: Support OpenRC.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/guix-install.sh (chk_init_sys): Detect OpenRC.
(sys_enable_guix_daemon): Install &amp; enable the Guix daemon on such
systems.
* etc/openrc/guix-daemon.in: New file.
* nix/local.mk: Add a rule for it.
(openrcservicedir, nodist_openrcservice_DATA): New variables.
(CLEANFILES, EXTRA_DIST): Add them.
* .gitignore: Ignore etc/openrc/guix-daemon.

Signed-off-by: Tobias Geerinckx-Rice &lt;me@tobias.gr&gt;
</span></span></td><td>Morgan Smith</td></tr>