--- a/mercurial/help.py Fri Mar 03 13:32:10 2017 -0500+++ b/mercurial/help.py Wed Mar 08 18:31:33 2017 -0500@@ -618,6 +618,8 @@ """ if keep is None: keep = []+ else:+ keep = list(keep) # make a copy so we can mutate this later fullname = name section = None subtopic = None