From 57cc7dfa057a4a044a5df6e172a7fef7197b5334 Mon Sep 17 00:00:00 2001
From: tk0miya <i.tkomiya@gmail.com>
Date: Tue, 19 Aug 2014 10:44:09 +0900
Subject: [PATCH] Fix RuntimeError with numbered circular toctree

---
 sphinx/environment.py |  4 +++-
 tests/test_build.py   | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/sphinx/environment.py b/sphinx/environment.py
index 72f5d240e..9c197477b 100644
--- a/sphinx/environment.py
+++ b/sphinx/environment.py
@@ -1444,6 +1444,7 @@ class BuildEnvironment:
         # a list of all docnames whose section numbers changed
         rewrite_needed = []
 
+        assigned = []
         old_secnumbers = self.toc_secnumbers
         self.toc_secnumbers = {}
 
@@ -1483,11 +1484,12 @@ class BuildEnvironment:
             if depth == 0:
                 return
             for (title, ref) in toctreenode['entries']:
-                if url_re.match(ref) or ref == 'self':
+                if url_re.match(ref) or ref == 'self' or ref in assigned:
                     # don't mess with those
                     continue
                 if ref in self.tocs:
                     secnums = self.toc_secnumbers[ref] = {}
+                    assigned.append(ref)
                     _walk_toc(self.tocs[ref], secnums, depth,
                               self.titles.get(ref))
                     if secnums != old_secnumbers.get(ref):
diff --git a/tests/test_build.py b/tests/test_build.py
index c8001271e..56fdf826b 100644
--- a/tests/test_build.py
+++ b/tests/test_build.py
@@ -79,3 +79,38 @@ def test_nonascii_path():
         app = TestApp(buildername=buildername, _copy_to_temp=True)
         yield _test_nonascii_path, app
         app.cleanup()
+
+
+@with_app(buildername='text', srcdir='(empty)')
+def test_circular_toctree(app):
+    contents = (".. toctree::\n"
+                "\n"
+                "   sub\n")
+    (app.srcdir / 'contents.rst').write_text(contents, encoding='utf-8')
+
+    contents = (".. toctree::\n"
+                "\n"
+                "   contents\n")
+    (app.srcdir / 'sub.rst').write_text(contents, encoding='utf-8')
+    app.builder.build_all()
+    warnings = "".join(app._warning.content)
+    assert 'circular toctree references detected, ignoring: sub <- contents <- sub' in warnings
+    assert 'circular toctree references detected, ignoring: contents <- sub <- contents' in warnings
+
+
+@with_app(buildername='text', srcdir='(empty)')
+def test_numbered_circular_toctree(app):
+    contents = (".. toctree::\n"
+                "   :numbered:\n"
+                "\n"
+                "   sub\n")
+    (app.srcdir / 'contents.rst').write_text(contents, encoding='utf-8')
+
+    contents = (".. toctree::\n"
+                "\n"
+                "   contents\n")
+    (app.srcdir / 'sub.rst').write_text(contents, encoding='utf-8')
+    app.builder.build_all()
+    warnings = "\n".join(app._warning.content)
+    assert 'circular toctree references detected, ignoring: sub <- contents <- sub' in warnings
+    assert 'circular toctree references detected, ignoring: contents <- sub <- contents' in warnings