gen: handle None in convert_yielded

2016-05-09 11:08:07 +00:00 · 2016-05-09 11:08:07 +00:00 · 447bf2e06b
parent c20c44d776
commit 447bf2e06b
1 changed files with 3 additions and 1 deletions
--- a/tornado/gen.py
+++ b/tornado/gen.py
@ -1215,7 +1215,9 @@ def convert_yielded(yielded):
    .. versionadded:: 4.1
    """
    # Lists and dicts containing YieldPoints were handled earlier.
-    if isinstance(yielded, (list, dict)):
+    if yielded is None:
+        return moment
+    elif isinstance(yielded, (list, dict)):
        return multi(yielded)
    elif is_future(yielded):
        return yielded