Close #6239: latex: Support to build Chinese documents

CHANGES

@@ -12,6 +12,7 @@ Incompatible changes
 * #6230: The anchor of term in glossary directive is changed if it is consisted
   by non-ASCII characters
 * #4550: html: Centering tables by default using CSS
+* #6239: latex: xelatex and xeCJK are used for Chinese documents by default
 
 Deprecated
 ----------
@@ -105,6 +106,7 @@ Features added
   full production rule
 * #6373: autosectionlabel: Allow suppression of warnings
 * coverage: Support a new ``coverage_ignore_pyobjects`` option
+* #6239: latex: Support to build Chinese documents
 
 Bugs fixed
 ----------

sphinx/builders/latex/__init__.py

@@ -180,12 +180,10 @@ class LaTeXBuilder(Builder):
         # Add special settings for latex_engine
         self.context.update(ADDITIONAL_SETTINGS.get(self.config.latex_engine, {}))
 
-        # for xelatex+French, don't use polyglossia by default
-        if self.config.latex_engine == 'xelatex':
-            if self.config.language:
-                if self.config.language[:2] == 'fr':
-                    self.context['polyglossia'] = ''
-                    self.context['babel'] = r'\usepackage{babel}'
+        # Add special settings for (latex_engine, language_code)
+        if self.config.language:
+            key = (self.config.latex_engine, self.config.language[:2])
+            self.context.update(ADDITIONAL_SETTINGS.get(key, {}))
 
         # Apply extension settings to context
         self.context['packages'] = self.usepackages
@@ -441,6 +439,8 @@ def default_latex_engine(config):
     """ Better default latex_engine settings for specific languages. """
     if config.language == 'ja':
         return 'platex'
+    elif (config.language or '').startswith('zh'):
+        return 'xelatex'
     else:
         return 'pdflatex'
 

sphinx/builders/latex/util.py

@@ -47,11 +47,13 @@ class ExtBabel(Babel):
             # polyglossia calls new orthography (Neue Rechtschreibung) as
             # german (with new spelling option).
             return 'german'
-        elif not language:
+        elif language:
+            return language
+        elif language_code.startswith('zh'):
+            return 'english'  # fallback to english (behaves like supported)
+        else:
             self.supported = False
             return 'english'  # fallback to english
-        else:
-            return language
 
     def get_mainlanguage_options(self):
         # type: () -> str

sphinx/writers/latex.py

@@ -216,7 +216,17 @@ ADDITIONAL_SETTINGS = {
         'fncychap':     '',
         'geometry':     '\\usepackage[dvipdfm]{geometry}',
     },
-}  # type: Dict[str, Dict[str, Any]]
+
+    # special settings for latex_engine + language_code
+    ('xelatex', 'fr'): {
+        # use babel instead of polyglossia by default
+        'polyglossia':  '',
+        'babel':        '\\usepackage{babel}',
+    },
+    ('xelatex', 'zh'): {
+        'fontenc':      '\\usepackage{xeCJK}',
+    },
+}  # type: Dict[Any, Dict[str, Any]]
 
 EXTRA_RE = re.compile(r'^(.*\S)\s+\(([^()]*)\)\s*$')
 

tests/test_build_latex.py

@@ -165,6 +165,16 @@ def test_latex_basic(app, status, warning):
     assert r'\renewcommand{\releasename}{}' in result
 
 
+@pytest.mark.sphinx('latex', testroot='basic', confoverrides={'language': 'zh'})
+def test_latex_additional_settings_for_language_code(app, status, warning):
+    app.builder.build_all()
+    result = (app.outdir / 'test.tex').text(encoding='utf8')
+    print(result)
+    print(status.getvalue())
+    print(warning.getvalue())
+    assert r'\usepackage{xeCJK}' in result
+
+
 @pytest.mark.sphinx('latex', testroot='latex-title')
 def test_latex_title_after_admonitions(app, status, warning):
     app.builder.build_all()