Force remote_user to be the currently user for connection=local

Fixes ansible-modules-core#4092

(cherry picked from commit 9248cde239)

lib/ansible/playbook/play_context.py

@@ -21,7 +21,9 @@
 from __future__ import (absolute_import, division, print_function)
 __metaclass__ = type
 
+import os
 import pipes
+import pwd
 import random
 import re
 import string
@@ -409,6 +411,12 @@ class PlayContext(Base):
         if new_info.port is None and C.DEFAULT_REMOTE_PORT is not None:
             new_info.port = int(C.DEFAULT_REMOTE_PORT)
 
+        # if the final connection type is local, reset the remote_user value
+        # to that of the currently logged in user, to ensure any become settings
+        # are obeyed correctly
+        if new_info.connection == 'local':
+            new_info.remote_user = pwd.getpwuid(os.getuid()).pw_name
+
         # special overrides for the connection setting
         if len(delegated_vars) > 0:
             # in the event that we were using local before make sure to reset the