From bfd35c6ce179d121b0795ddb90f594e3c9543e34 Mon Sep 17 00:00:00 2001
From: Takeshi KOMIYA <i.tkomiya@gmail.com>
Date: Sat, 1 Dec 2018 18:57:18 +0900
Subject: [PATCH] Add role manipulator directives to sphinx.util.docutils

---
 sphinx/application.py   |  8 ++++----
 sphinx/util/docutils.py | 16 ++++++++++++++++
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/sphinx/application.py b/sphinx/application.py
index ec793b19e..1cabca6ad 100644
--- a/sphinx/application.py
+++ b/sphinx/application.py
@@ -21,7 +21,7 @@ from inspect import isclass
 from io import StringIO
 from os import path
 
-from docutils.parsers.rst import Directive, directives, roles
+from docutils.parsers.rst import Directive, roles
 
 import sphinx
 from sphinx import package_dir, locale
@@ -651,15 +651,15 @@ class Sphinx:
         """
         logger.debug('[app] adding directive: %r',
                      (name, obj, content, arguments, options))
-        if name in directives._directives and not override:
+        if not override and docutils.is_directive_registered(name):
             logger.warning(__('directive %r is already registered, it will be overridden'),
                            name, type='app', subtype='add_directive')
 
         if not isclass(obj) or not issubclass(obj, Directive):
             directive = directive_helper(obj, content, arguments, **options)
-            directives.register_directive(name, directive)
+            docutils.register_directive(name, directive)
         else:
-            directives.register_directive(name, obj)
+            docutils.register_directive(name, obj)
 
     def add_role(self, name, role, override=False):
         # type: (unicode, Any, bool) -> None
diff --git a/sphinx/util/docutils.py b/sphinx/util/docutils.py
index 07be9f092..7b1edfc34 100644
--- a/sphinx/util/docutils.py
+++ b/sphinx/util/docutils.py
@@ -67,6 +67,22 @@ def docutils_namespace():
             additional_nodes.discard(node)
 
 
+def is_directive_registered(name):
+    # type: (unicode) -> bool
+    """Check the *name* directive is already registered."""
+    return name in directives._directives
+
+
+def register_directive(name, directive):
+    # type: (unicode, Type[Directive]) -> None
+    """Register a directive to docutils.
+
+    This modifies global state of docutils.  So it is better to use this
+    inside ``docutils_namespace()`` to prevent side-effects.
+    """
+    directives.register_directive(name, directive)
+
+
 def is_role_registered(name):
     # type: (unicode) -> bool
     """Check the *name* role is already registered."""