From 3842a180bed17c2a526bdb46cadea4496fc2e541 Mon Sep 17 00:00:00 2001
From: Tal Einat <taleinat@gmail.com>
Date: Sun, 11 Aug 2019 14:18:29 +0300
Subject: [PATCH] bpo-37821: IDLE completion namespace fix

---
 Lib/idlelib/autocomplete.py                      | 16 +++++++++++++---
 Lib/idlelib/run.py                               |  2 +-
 .../2019-08-11-14-20-28.bpo-37821.OVbIt_.rst     |  2 ++
 3 files changed, 16 insertions(+), 4 deletions(-)
 create mode 100644 Misc/NEWS.d/next/IDLE/2019-08-11-14-20-28.bpo-37821.OVbIt_.rst

diff --git a/Lib/idlelib/autocomplete.py b/Lib/idlelib/autocomplete.py
index c623d45a153423..0dac2a4bfa2efa 100644
--- a/Lib/idlelib/autocomplete.py
+++ b/Lib/idlelib/autocomplete.py
@@ -30,8 +30,9 @@
 
 class AutoComplete:
 
-    def __init__(self, editwin=None):
+    def __init__(self, editwin=None, namespace=None):
         self.editwin = editwin
+        self.namespace = namespace
         if editwin is not None:   # not in subprocess or no-gui test
             self.text = editwin.text
         self.autocompletewindow = None
@@ -208,8 +209,17 @@ def fetch_completions(self, what, mode):
             return smalll, bigl
 
     def get_entity(self, name):
-        "Lookup name in a namespace spanning sys.modules and __main.dict__."
-        return eval(name, {**sys.modules, **__main__.__dict__})
+        """Evaluate an expression in a the execution namespace."""
+        namespace = self.namespace
+        if namespace is None:
+            try:
+                # Fallback when running without a subprocess.
+                namespace = self.editwin.flist.pyshell.interp.locals
+            except AttributeError:
+                # Fallback when there isn't a running shell.
+                namespace = {**sys.modules, **__main__.__dict__}
+
+        return eval(name, namespace)
 
 
 AutoComplete.reload()
diff --git a/Lib/idlelib/run.py b/Lib/idlelib/run.py
index 41e0ded4402937..846dc4699d879e 100644
--- a/Lib/idlelib/run.py
+++ b/Lib/idlelib/run.py
@@ -539,7 +539,7 @@ def __init__(self, rpchandler):
         self.rpchandler = rpchandler
         self.locals = __main__.__dict__
         self.calltip = calltip.Calltip()
-        self.autocomplete = autocomplete.AutoComplete()
+        self.autocomplete = autocomplete.AutoComplete(namespace=self.locals)
 
     def runcode(self, code):
         global interruptable
diff --git a/Misc/NEWS.d/next/IDLE/2019-08-11-14-20-28.bpo-37821.OVbIt_.rst b/Misc/NEWS.d/next/IDLE/2019-08-11-14-20-28.bpo-37821.OVbIt_.rst
new file mode 100644
index 00000000000000..87e05eac64d7dd
--- /dev/null
+++ b/Misc/NEWS.d/next/IDLE/2019-08-11-14-20-28.bpo-37821.OVbIt_.rst
@@ -0,0 +1,2 @@
+Fix the namespace used for completions to be that of the running shell, when
+a shell window exists.