Issue #24972: New option is only valid in tk 8.5+.

diff --git a/Lib/idlelib/EditorWindow.py b/Lib/idlelib/EditorWindow.py
index d742dd64f16f79af24ceb199d620c2ad337426ef..a634d1f323a0957205a1e703a85e1f3b2a9e3c33 100644 (file)
--- a/Lib/idlelib/EditorWindow.py
+++ b/Lib/idlelib/EditorWindow.py
@@ -755,8 +755,10 @@ class EditorWindow(object):
             insertbackground=cursor_color,
             selectforeground=select_colors['foreground'],
             selectbackground=select_colors['background'],
-            inactiveselectbackground=select_colors['background'],
             )
+        if TkVersion >= 8.5:
+            self.text.config(
+                inactiveselectbackground=select_colors['background'])
 
     IDENTCHARS = string.ascii_letters + string.digits + "_"