Issue #15861: tkinter now correctly works with lists and tuples containing
strings with whitespaces, backslashes or unbalanced braces.
diff --git a/Lib/lib-tk/Tkinter.py b/Lib/lib-tk/Tkinter.py
index e5c2e51..fcb320f 100644
--- a/Lib/lib-tk/Tkinter.py
+++ b/Lib/lib-tk/Tkinter.py
@@ -41,6 +41,7 @@
 TclError = _tkinter.TclError
 from types import *
 from Tkconstants import *
+import re
 
 wantobjects = 1
 
@@ -58,6 +59,37 @@
 except AttributeError: _tkinter.deletefilehandler = None
 
 
+_magic_re = re.compile(r'([\\{}])')
+_space_re = re.compile(r'([\s])')
+
+def _join(value):
+    """Internal function."""
+    return ' '.join(map(_stringify, value))
+
+def _stringify(value):
+    """Internal function."""
+    if isinstance(value, (list, tuple)):
+        if len(value) == 1:
+            value = _stringify(value[0])
+            if value[0] == '{':
+                value = '{%s}' % value
+        else:
+            value = '{%s}' % _join(value)
+    else:
+        if isinstance(value, basestring):
+            value = unicode(value)
+        else:
+            value = str(value)
+        if not value:
+            value = '{}'
+        elif _magic_re.search(value):
+            # add '\' before special characters and spaces
+            value = _magic_re.sub(r'\\\1', value)
+            value = _space_re.sub(r'\\\1', value)
+        elif value[0] == '"' or _space_re.search(value):
+            value = '{%s}' % value
+    return value
+
 def _flatten(tuple):
     """Internal function."""
     res = ()
@@ -1086,7 +1118,7 @@
                             nv.append('%d' % item)
                         else:
                             # format it to proper Tcl code if it contains space
-                            nv.append(('{%s}' if ' ' in item else '%s') % item)
+                            nv.append(_stringify(item))
                     else:
                         v = ' '.join(nv)
                 res = res + ('-'+k, v)