From 704619878e310b0a6ab2934c81a8d4c560927650 Mon Sep 17 00:00:00 2001
From: Georg Brandl <georg@python.org>
Date: Wed, 31 Dec 2014 15:04:48 +0100
Subject: [PATCH] Fix memory leak during parallel writing with multiplied
 warnings.

---
 sphinx/builders/__init__.py | 4 +++-
 sphinx/util/parallel.py     | 8 ++++++--
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/sphinx/builders/__init__.py b/sphinx/builders/__init__.py
index 5370dd70f..bbb9b3117 100644
--- a/sphinx/builders/__init__.py
+++ b/sphinx/builders/__init__.py
@@ -357,9 +357,11 @@ class Builder(object):
 
     def _write_parallel(self, docnames, warnings, nproc):
         def write_process(docs):
+            local_warnings = []
+            self.env.set_warnfunc(lambda *args: local_warnings.append(args))
             for docname, doctree in docs:
                 self.write_doc(docname, doctree)
-            return warnings
+            return local_warnings
 
         def add_warnings(docs, wlist):
             warnings.extend(wlist)
diff --git a/sphinx/util/parallel.py b/sphinx/util/parallel.py
index 5f9e8effd..7e238ab18 100644
--- a/sphinx/util/parallel.py
+++ b/sphinx/util/parallel.py
@@ -101,7 +101,9 @@ class ParallelTasks(object):
             del self._threads[tid]
             if exc:
                 raise SphinxParallelError(*result)
-            self._result_funcs.pop(tid)(arg, result)
+            result_func = self._result_funcs.pop(tid)(arg, result)
+            if result_func:
+                result_func(result)
             self._nprocessed += 1
 
     def join(self):
@@ -110,7 +112,9 @@ class ParallelTasks(object):
             del self._threads[tid]
             if exc:
                 raise SphinxParallelError(*result)
-            self._result_funcs.pop(tid)(arg, result)
+            result_func = self._result_funcs.pop(tid)(arg, result)
+            if result_func:
+                result_func(result)
             self._nprocessed += 1
 
         # there shouldn't be any threads left...