From 12dde8afdb0a7bb5576e2656692c3478c69d8cc3 Mon Sep 17 00:00:00 2001
From: vitaut <victor.zverovich@gmail.com>
Date: Fri, 16 Oct 2015 06:58:12 -0700
Subject: [PATCH] Make sphinx_rtd_theme optional

---
 setup.py          | 1 -
 sphinx/theming.py | 9 +++++++--
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/setup.py b/setup.py
index cc977f50f..73c57276c 100644
--- a/setup.py
+++ b/setup.py
@@ -53,7 +53,6 @@ requires = [
     'snowballstemmer>=1.1',
     'babel>=1.3,!=2.0',
     'alabaster>=0.7,<0.8',
-    'sphinx_rtd_theme>=0.1,<2.0',
 ]
 extras_require = {
     # Environment Marker works for wheel 0.24 or later
diff --git a/sphinx/theming.py b/sphinx/theming.py
index 49bd707d0..6be331194 100644
--- a/sphinx/theming.py
+++ b/sphinx/theming.py
@@ -27,7 +27,6 @@ from sphinx import package_dir
 from sphinx.errors import ThemeError
 
 import alabaster
-import sphinx_rtd_theme
 
 NODEFAULT = object()
 THEMECONF = 'theme.conf'
@@ -71,7 +70,13 @@ class Theme(object):
 
     @classmethod
     def load_extra_theme(cls, name):
-        if name in ('alabaster', 'sphinx_rtd_theme'):
+        themes = ['alabaster']
+        try:
+            import sphinx_rtd_theme
+            themes.append('sphinx_rtd_theme')
+        except ImportError:
+            pass
+        if name in themes:
             if name == 'alabaster':
                 themedir = alabaster.get_path()
                 # alabaster theme also requires 'alabaster' extension, it will be loaded