commit 24a54da9452efb21d30dc56c6b9d0977d08ae452
author Terry Jan Reedy <tjreedy@udel.edu> Thu Aug 02 23:40:20 2018 -0400
committer GitHub <noreply@github.com> Thu Aug 02 23:40:20 2018 -0400
tree 0a26d9126ac16ade3077a81fa4c501f5d5530fa8
parent dd4d8b4d80065409dae69f966fd7617e5b3d97f1

 [2.7] bpo-34275: Make IDLE calltips always visible on Mac. (GH-8639) (GH-8644)

Some MacOS-tk combinations need .update_idletasks().
The call is both unneeded and innocuous on Linux and Windows.
Patch by Kevin Walzer.

(cherry picked from commit 9beaef6225cdae972b1cccd5310828cc29bf9d33)
Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>

Lib/idlelib/CallTipWindow.py

diff --git a/Lib/idlelib/CallTipWindow.py b/Lib/idlelib/CallTipWindow.py
index e63164b..2a453d0 100644
--- a/Lib/idlelib/CallTipWindow.py
+++ b/Lib/idlelib/CallTipWindow.py
@@ -72,6 +72,7 @@
                            background="#ffffe0", relief=SOLID, borderwidth=1,
                            font = self.widget['font'])
         self.label.pack()
+        tw.update_idletasks()
         tw.lift()  # work around bug in Tk 8.5.18+ (issue #24570)
 
         self.checkhideid = self.widget.bind(CHECKHIDE_VIRTUAL_EVENT_NAME,