Fixed #9644: fix a thread sync issue in the locmem cache. Thanks, mrts.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@10333 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/core/cache/backends/locmem.py

@@ -57,9 +57,12 @@ class CacheClass(BaseCache):
         finally:
             self._lock.reader_leaves()
         self._lock.writer_enters()
+        try:
             try:
                 del self._cache[key]
                 del self._expire_info[key]
+            except KeyError:
+                pass
             return default
         finally:
             self._lock.writer_leaves()