Issue 6037: MutableSequence.__iadd__ should return self.

diff --git a/Lib/_abcoll.py b/Lib/_abcoll.py
index a355be9a79b37b43bc011236e128870ad932369d..d8cdc98c4cf0797e80537786dac95abcdf9ae76f 100644 (file)
--- a/Lib/_abcoll.py
+++ b/Lib/_abcoll.py
@@ -557,5 +557,6 @@ class MutableSequence(Sequence):
 
     def __iadd__(self, values):
         self.extend(values)
+        return self
 
 MutableSequence.register(list)