When sing IDLE in Ubuntu (Jaunty) if you open the Class Browser and
double click on a class or function name, the corresponding section is
highlighted in the code in the Editor Window.

If you again double click on another class or function name, the new
code section should be highlighted in the Editor Window but isn't.
Nothing happens. You have to first close the Class Browser window,
reopen it and double click on another name to select it the Editor Window.

In the Windows versions, successive double clicking will highlight the
desired selection in the Class Browser window.

TreeNode class which is used in IDLE class browser create a window for a text label on each single click and apparently under Ubuntu tcl looses first left button click and therefore doesn't generate left buttond double click event.

In this patch I make changes to the TreeNode class so it creates a window for a text label only when needed (i.e. during initialization or when it was delete after "collapse" command)

This issue doesn't describe the above situation on Ubuntu 14.04.
I use IDLE 3.4.0 and Python 3.4.0. When the Class browser is opened and if the function name or class name is double clicked, it highlights the corresponding section in the editor. It's perfectly working when we do same action on different function names or class names without opening class browser another time.

Jason or Serge, does this issue still exist with a current release (3.4.2 or 2.7.8) with a recent tcl/tk. (The Tk version is listed on About Idle.)

Behavior described in msg229434 is right. Tested on Ubuntu 14.04 64bit with Python version 3.5.0a, TkVersion=8.5 and TclVersion=8.5.

It appears that this could be closed then. But I would like to look at the patch first if I can get to it.

(In 3.6, TreeWidget.py became tree.py.)
Even though IDLE trees now appear to work correctly, including on Ubuntu, I am concerned about possible memory leaks, which are usually detected by repeatedly running a module's test file. Test_tree does not leak now, but it does not do much. In particular, it does not expand and contract items and move selections. TreeNode.draw has this note: "This leaks bindings until canvas is deleted", and I wonder if the same could be true in .drawtext.

Tree.py currently has these notes at the top:
# - keep track of object ids to allow more careful cleaning
# - optimize tree redraw after expand of subnode
Currently, self.text_id is saved, but not used. Reusing canvas items should be more efficient.

I won't edit tree.py immediately, as I intend to try using ttk.Treeview as a replacement. But we might instead update tree.py with ttk components. In the meanwhile, I will leave this open.