diff --git a/docs/vendor/sphinxcontrib/fulltoc.py b/docs/vendor/sphinxcontrib/fulltoc.py
new file mode 100644
index 0000000000..9f2ddc4d27
--- /dev/null
+++ b/docs/vendor/sphinxcontrib/fulltoc.py
@@ -0,0 +1,90 @@
+# -*- encoding: utf-8 -*-
+#
+# Copyright © 2012 New Dream Network, LLC (DreamHost)
+#
+# Author: Doug Hellmann <doug.hellmann@dreamhost.com>
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+
+from sphinx import addnodes
+
+
+def html_page_context(app, pagename, templatename, context, doctree):
+    """Event handler for the html-page-context signal.
+    Modifies the context directly.
+     - Replaces the 'toc' value created by the HTML builder with one
+       that shows all document titles and the local table of contents.
+     - Sets display_toc to True so the table of contents is always
+       displayed, even on empty pages.
+     - Replaces the 'toctree' function with one that uses the entire
+       document structure, ignores the maxdepth argument, and uses
+       only prune and collapse.
+    """
+    rendered_toc = get_rendered_toctree(app.builder, pagename)
+    context['toc'] = rendered_toc
+    context['display_toc'] = True  # force toctree to display
+
+    if "toctree" not in context:
+        # json builder doesn't use toctree func, so nothing to replace
+        return
+
+    def make_toctree(collapse=True):
+        return get_rendered_toctree(app.builder,
+                                    pagename,
+                                    prune=False,
+                                    collapse=collapse,
+                                    )
+
+    context['toctree'] = make_toctree
+
+
+def get_rendered_toctree(builder, docname, prune=False, collapse=True):
+    """Build the toctree relative to the named document,
+    with the given parameters, and then return the rendered
+    HTML fragment.
+    """
+    fulltoc = build_full_toctree(builder,
+                                 docname,
+                                 prune=prune,
+                                 collapse=collapse,
+                                 )
+    rendered_toc = builder.render_partial(fulltoc)['fragment']
+    return rendered_toc
+
+
+def build_full_toctree(builder, docname, prune, collapse):
+    """Return a single toctree starting from docname containing all
+    sub-document doctrees.
+    """
+    env = builder.env
+    doctree = env.get_doctree(env.config.master_doc)
+    toctrees = []
+    for toctreenode in doctree.traverse(addnodes.toctree):
+        toctree = env.resolve_toctree(docname, builder, toctreenode,
+                                      collapse=collapse,
+                                      prune=prune,
+                                      )
+        toctrees.append(toctree)
+    if not toctrees:
+        return None
+    result = toctrees[0]
+    for toctree in toctrees[1:]:
+        if toctree:
+            result.extend(toctree.children)
+    env.resolve_references(result, docname, builder)
+    return result
+
+
+def setup(app):
+    app.connect('html-page-context', html_page_context)