docs: conf.py: only use CJK if the font is available
If we try to build a book with asian characters with XeLaTeX
and the font is not available, it will produce an error.
So, instead, add a logic at conf.py to detect if the proper
font is installed.
This will avoid an error while building the document, although
the result may not be readable.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
diff --git a/Documentation/conf.py b/Documentation/conf.py
index fa0a42b..a8fe845 100644
--- a/Documentation/conf.py
+++ b/Documentation/conf.py
@@ -16,6 +16,8 @@
import os
import sphinx
+from subprocess import check_output
+
# Get Sphinx version
major, minor, patch = sphinx.version_info[:3]
@@ -276,13 +278,20 @@
\\setsansfont{DejaVu Sans}
\\setromanfont{DejaVu Serif}
\\setmonofont{DejaVu Sans Mono}
+ '''
+}
+# At least one book (translations) may have Asian characters
+# with are only displayed if xeCJK is used
+
+cjk_cmd = check_output(['fc-list', '--format="%{family[0]}\n"']).decode('utf-8', 'ignore')
+if cjk_cmd.find("Noto Sans CJK SC") >= 0:
+ print ("enabling CJK for LaTeX builder")
+ latex_elements['preamble'] += '''
% This is needed for translations
\\usepackage{xeCJK}
\\setCJKmainfont{Noto Sans CJK SC}
-
'''
-}
# Fix reference escape troubles with Sphinx 1.4.x
if major == 1 and minor > 3: