Use platex by default if language is "ja"

sphinx/builders/latex.py

@@ -263,8 +263,10 @@ def setup(app):
     app.add_builder(LaTeXBuilder)
     app.connect('builder-inited', validate_config_values)
 
-    app.add_config_value('latex_engine', 'pdflatex', None,
-                         ENUM('pdflatex', 'xelatex', 'lualatex'))
+    app.add_config_value('latex_engine',
+                         lambda self: 'pdflatex' if self.language != 'ja' else 'platex',
+                         None,
+                         ENUM('pdflatex', 'xelatex', 'lualatex', 'platex'))
     app.add_config_value('latex_documents',
                          lambda self: [(self.master_doc, make_filename(self.project) + '.tex',
                                         self.project, '', 'manual')],

sphinx/texinputs/Makefile_t

@@ -16,8 +16,13 @@ LATEX = latex
 PDFLATEX = {{ latex_engine }}
 MAKEINDEX = makeindex
 
+{% if latex_engine == 'platex' %}
+all: all-pdf-ja
+all-pdf: all-pdf-ja
+{% else %}
 all: $(ALLPDF)
 all-pdf: $(ALLPDF)
+{% endif -%}
 all-dvi: $(ALLDVI)
 all-ps: $(ALLPS)