bpo-33096 Modify ttk.Treeview.insert

Allow ttk.Treeview.insert to insert False iid.
Note iid=0 and iid=false would be same

Author: plusminushalf

Lib/tkinter/test/test_ttk/test_widgets.py

@@ -1662,6 +1662,17 @@ def test_insert_item(self):
             self.tv.insert('', 'end', text=value), text=None),
             value)
 
+        # test for values which are not None
+        itemid = self.tv.insert('', 'end', 0)
+        self.assertEqual(itemid, '0')
+        itemid = self.tv.insert('', 'end', 0.0)
+        self.assertEqual(itemid, '0.0')
+        # this is because False is resolveds to 0 and element with 0 id is already present
+        self.assertRaises(tkinter.TclError, self.tv.insert, '', '',
+            False)
+        self.assertRaises(tkinter.TclError, self.tv.insert, '', '',
+            '')
+
 
     def test_selection(self):
         self.assertRaises(TypeError, self.tv.selection, 'spam')

Lib/tkinter/ttk.py

@@ -1361,7 +1361,7 @@ def insert(self, parent, index, iid=None, **kw):
         already exist in the tree. Otherwise, a new unique identifier
         is generated."""
         opts = _format_optdict(kw)
-        if iid:
+        if iid is not None:
             res = self.tk.call(self._w, "insert", parent, index,
                 "-id", iid, *opts)
         else: