Index: Lib/lib-tk/Tkinter.py
===================================================================
--- Lib/lib-tk/Tkinter.py	(revision 65077)
+++ Lib/lib-tk/Tkinter.py	(working copy)
@@ -1111,7 +1111,7 @@
         w = self
         while w.master: w = w.master
         return w
-    _subst_format = ('%#', '%b', '%f', '%h', '%k',
+    _subst_format = ('%#', '%b', '%d', '%f', '%h', '%k',
              '%s', '%t', '%w', '%x', '%y',
              '%A', '%E', '%K', '%N', '%W', '%T', '%X', '%Y', '%D')
     _subst_format_str = " ".join(_subst_format)
@@ -1128,11 +1128,12 @@
             except ValueError:
                 return s
 
-        nsign, b, f, h, k, s, t, w, x, y, A, E, K, N, W, T, X, Y, D = args
-        # Missing: (a, c, d, m, o, v, B, R)
+        nsign, b, d, f, h, k, s, t, w, x, y, A, E, K, N, W, T, X, Y, D = args
+        # Missing: (a, c, m, o, v, B, R)
         e = Event()
         # serial field: valid vor all events
         # number of button: ButtonPress and ButtonRelease events only
+        # data: data is valid for all virtual events
         # height field: Configure, ConfigureRequest, Create,
         # ResizeRequest, and Expose events only
         # keycode field: KeyPress and KeyRelease events only
@@ -1146,6 +1147,15 @@
         # KeyRelease,and Motion events
         e.serial = getint(nsign)
         e.num = getint_event(b)
+
+        if d:
+            try:
+                e.data = self.nametowidget(d)
+            except KeyError:
+                # value passed to the data option is not a widget, take it
+                # as the detail field
+                e.data = None
+                e.detail = d
         try: e.focus = getboolean(f)
         except TclError: pass
         e.height = getint_event(h)