bpo-36405: IDLE - Restore __main__ and add tests (GH-12518)

Fix error in commit 2b75155 noticed by Serhiy Storchaka.
(cherry picked from commit 0fe4513d9a5510ae91c0da7eb0433f79a6d4dda9)

Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>

1 files changed, 5 insertions, 3 deletions

diff --git a/Lib/idlelib/autocomplete.py b/Lib/idlelib/autocomplete.py
index 6751928..d57e9c9 100644
--- a/Lib/idlelib/autocomplete.py
+++ b/Lib/idlelib/autocomplete.py
@@ -3,6 +3,7 @@
 Either on demand or after a user-selected delay after a key character,
 pop up a list of candidates.
 """
+import __main__
 import os
 import string
 import sys
@@ -181,7 +182,8 @@ class AutoComplete:
         else:
             if mode == COMPLETE_ATTRIBUTES:
                 if what == "":
-                    namespace = {**__builtins__.__dict__, **globals()}
+                    namespace = {**__main__.__builtins__.__dict__,
+                                 **__main__.__dict__}
                     bigl = eval("dir()", namespace)
                     bigl.sort()
                     if "__all__" in bigl:
@@ -216,8 +218,8 @@ class AutoComplete:
             return smalll, bigl
 
     def get_entity(self, name):
-        "Lookup name in a namespace spanning sys.modules and globals()."
-        return eval(name, {**sys.modules, **globals()})
+        "Lookup name in a namespace spanning sys.modules and __main.dict__."
+        return eval(name, {**sys.modules, **__main__.__dict__})
 
 
 AutoComplete.reload()