merge with master

Author: giwa

python/pyspark/streaming/dstream.py

@@ -431,6 +431,7 @@ def __init__(self, prev, func, preservesPartitioning=False):
             self._prev_jrdd_deserializer = prev._jrdd_deserializer
         else:
             prev_func = prev.func
+            
             def pipeline_func(split, iterator):
                 return func(split, prev_func(split, iterator))
             self.func = pipeline_func