bpo-46996: IDLE: Drop workarounds for old Tk versions (GH-31962)

Lib/idlelib/configdialog.py

@@ -1588,7 +1588,7 @@ def create_page_windows(self):
                     win_height_int: Entry > win_height
                 frame_cursor: Frame
                     indent_title: Label
-                    indent_chooser: Spinbox (Combobox < 8.5.9) > indent_spaces
+                    indent_chooser: Spinbox > indent_spaces
                     blink_on: Checkbutton > cursor_blink
                 frame_autocomplete: Frame
                     auto_wait_title: Label

Lib/idlelib/macosx.py

@@ -68,27 +68,6 @@ def isXQuartz():
     return _tk_type == "xquartz"
 
 
-def tkVersionWarning(root):
-    """
-    Returns a string warning message if the Tk version in use appears to
-    be one known to cause problems with IDLE.
-    1. Apple Cocoa-based Tk 8.5.7 shipped with Mac OS X 10.6 is unusable.
-    2. Apple Cocoa-based Tk 8.5.9 in OS X 10.7 and 10.8 is better but
-        can still crash unexpectedly.
-    """
-
-    if isCocoaTk():
-        patchlevel = root.tk.call('info', 'patchlevel')
-        if patchlevel not in ('8.5.7', '8.5.9'):
-            return False
-        return ("WARNING: The version of Tcl/Tk ({0}) in use may"
-                " be unstable.\n"
-                "Visit https://www.python.org/download/mac/tcltk/"
-                " for current information.".format(patchlevel))
-    else:
-        return False
-
-
 def readSystemPreferences():
     """
     Fetch the macOS system preferences.

Lib/idlelib/pyshell.py

@@ -22,15 +22,6 @@
         pass
 
 from tkinter import messagebox
-if TkVersion < 8.5:
-    root = Tk()  # otherwise create root in main
-    root.withdraw()
-    from idlelib.run import fix_scaling
-    fix_scaling(root)
-    messagebox.showerror("Idle Cannot Start",
-            "Idle requires tcl/tk 8.5+, not %s." % TkVersion,
-            parent=root)
-    raise SystemExit(1)
 
 from code import InteractiveInterpreter
 import itertools
@@ -1690,11 +1681,6 @@ def main():
         # the IDLE shell window; this is less intrusive than always
         # opening a separate window.
 
-        # Warn if using a problematic OS X Tk version.
-        tkversionwarning = macosx.tkVersionWarning(root)
-        if tkversionwarning:
-            shell.show_warning(tkversionwarning)
-
         # Warn if the "Prefer tabs when opening documents" system
         # preference is set to "Always".
         prefer_tabs_preference_warning = macosx.preferTabsPreferenceWarning()