Fix broken LateX customization via templates (closes: #4795)

sphinx/writers/latex.py

@@ -927,8 +927,9 @@ class LaTeXTranslator(nodes.NodeVisitor):
 
     def render(self, template_name, variables):
         # type: (unicode, Dict) -> unicode
-        for template_path in self.builder.config.templates_path:
+        for template_dir in self.builder.config.templates_path:
-            template = path.join(template_path, template_name)
+            template = path.join(self.builder.srcdir, template_dir,
+                                 template_name)
             if path.exists(template):
                 return LaTeXRenderer().render(template, variables)
 

tests/roots/test-latex-table/_mytemplates/latex/longtable.tex_t

@@ -0,0 +1 @@
+SALUT LES COPAINS

tests/test_build_latex.py

@@ -1098,6 +1098,30 @@ def test_latex_table_complex_tables(app, status, warning):
     assert actual == expected
 
 
+@pytest.mark.sphinx('latex', testroot='latex-table',
+                    confoverrides={'templates_path': ['_mytemplates/latex']})
+def test_latex_table_custom_template_caseA(app, status, warning):
+    app.builder.build_all()
+    result = (app.outdir / 'test.tex').text(encoding='utf8')
+    assert 'SALUT LES COPAINS' in result
+
+
+@pytest.mark.sphinx('latex', testroot='latex-table',
+                    confoverrides={'templates_path': ['_mytemplates']})
+def test_latex_table_custom_template_caseB(app, status, warning):
+    app.builder.build_all()
+    result = (app.outdir / 'test.tex').text(encoding='utf8')
+    assert 'SALUT LES COPAINS' not in result
+
+
+@pytest.mark.sphinx('latex', testroot='latex-table')
+@pytest.mark.test_params(shared_result='latex-table')
+def test_latex_table_custom_template_caseC(app, status, warning):
+    app.builder.build_all()
+    result = (app.outdir / 'test.tex').text(encoding='utf8')
+    assert 'SALUT LES COPAINS' not in result
+
+
 @pytest.mark.sphinx('latex', testroot='directives-raw')
 def test_latex_raw_directive(app, status, warning):
     app.builder.build_all()