Issue 6037: MutableSequence.__iadd__ should return self.

diff --git a/Lib/_abcoll.py b/Lib/_abcoll.py
index 990ff009824b95d6913a3aa089a498e1d921fd08..692a0d79673ea12209973cb8e2cb3a578eba0003 100644 (file)
--- a/Lib/_abcoll.py
+++ b/Lib/_abcoll.py
@@ -560,5 +560,6 @@ class MutableSequence(Sequence):
 
     def __iadd__(self, values):
         self.extend(values)
+        return self
 
 MutableSequence.register(list)