Comment 1 for bug 401032

I think that you should invalidate the edit button, when the item has not been selected.
And, after the branch is switched, the selection has been released.

=== modified file lib/wt_browser.py
--- lib/wt_browser.py 2009-07-16 12:31:36 +0000
+++ lib/wt_browser.py 2009-07-18 09:56:41 +0000
@@ -152,9 +152,13 @@
             self.stacked.setCurrentIndex(1)
             index = self.model.index(path)
             self.view.setRootIndex(index)
+ self.view.selectionModel().reset()
         self._root = path
         self._selected_fileinfo = None
+ self._edit_button.setEnabled(False)