From 9ccff74f66a55ea84276291c3d7ec474e675d621 Mon Sep 17 00:00:00 2001
From: Takeshi KOMIYA <i.tkomiya@gmail.com>
Date: Sat, 19 May 2018 22:50:10 +0900
Subject: [PATCH] Fix #4946: py domain: type field could not handle "None" as a
 type

---
 CHANGES                  |  1 +
 sphinx/domains/python.py | 10 +++++++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/CHANGES b/CHANGES
index 9f2c96dea..f9b6e6af5 100644
--- a/CHANGES
+++ b/CHANGES
@@ -32,6 +32,7 @@ Bugs fixed
   LaTeX engine crashed
 * #4978: latex: shorthandoff is not set up for Brazil locale
 * #4928: i18n: Ignore dot-directories like .git/ in LC_MESSAGES/
+* #4946: py domain: type field could not handle "None" as a type
 
 Testing
 --------
diff --git a/sphinx/domains/python.py b/sphinx/domains/python.py
index 2b46596af..1d1f28b03 100644
--- a/sphinx/domains/python.py
+++ b/sphinx/domains/python.py
@@ -156,7 +156,15 @@ class PyGroupedField(PyXrefMixin, GroupedField):
 
 
 class PyTypedField(PyXrefMixin, TypedField):
-    pass
+    def make_xref(self, rolename, domain, target,
+                  innernode=nodes.emphasis, contnode=None, env=None):
+        # type: (unicode, unicode, unicode, nodes.Node, nodes.Node, BuildEnvironment) ->  nodes.Node  # NOQA
+        if rolename == 'class' and target == 'None':
+            # None is not a type, so use obj role instead.
+            rolename = 'obj'
+
+        return super(PyTypedField, self).make_xref(rolename, domain, target,
+                                                   innernode, contnode, env)
 
 
 class PyObject(ObjectDescription):