Peter Haight discovered that this code uses a mutable default for cnf

and then (under certain circumstances) can clobber the default!
He also submitted this patch as PR#82.

diff --git a/Lib/lib-tk/ScrolledText.py b/Lib/lib-tk/ScrolledText.py
index f1c2bb08afe5739a1143dd4ff7b56745bd87212a..05b728a5ab17012576321e7829971e362613e0fc 100644 (file)
--- a/Lib/lib-tk/ScrolledText.py
+++ b/Lib/lib-tk/ScrolledText.py
@@ -14,7 +14,9 @@ from Tkinter import *
 from Tkinter import _cnfmerge
 
 class ScrolledText(Text):
-       def __init__(self, master=None, cnf={}, **kw):
+       def __init__(self, master=None, cnf=None, **kw):
+               if cnf is None:
+                       cnf = {}
                if kw:
                        cnf = _cnfmerge((cnf, kw))
                fcnf = {}