Function "sort lines" crashes when nothing selected

[LOVEJesus]

I have applied the function "Sort Lines", from the "Edit" menu, without selecting text and an error message has popped up containing the text below.
I believe some exception has not been caught, when "Sort lines" is clicked and no text is selected.

Greetings and Blessings,
Juan

Error message:

This is zim 0.63
Platform: posix
Locale: en_GB UTF-8
FS encoding: UTF-8
Python: (2, 7, 3, 'final', 0)
Gtk: (2, 24, 10)
Pygtk: (2, 24, 0)
No bzr version-info found

======= Traceback =======
  File "/usr/lib/pymodules/python2.7/zim/actions.py", line 55, in func
    self.func(instance, *arg, **kwarg)
  File "/usr/lib/pymodules/python2.7/zim/plugins/linesorter.py", line 57, in sort_selected_lines
    MessageDialog(self.ui,
AttributeError: 'MainWindowExtension' object has no attribute 'ui'

[Beth (beth-arronaz)]

I'm still getting this bug on 0.65:

This is zim 0.65
Platform: posix
Locale: pt_BR UTF-8
FS encoding: UTF-8
Python: (2, 7, 11, 'final', 0)
Gtk: (2, 24, 29)
Pygtk: (2, 24, 0)
Zim revision is:
  branch: zim-trunk
  revision: 805 <email address hidden>
  date: 2015-11-01 15:42:45 +0100

======= Traceback =======
  File "/usr/lib/python2.7/site-packages/zim/actions.py", line 109, in func
    self.func(instance, *arg, **kwarg)
  File "/usr/lib/python2.7/site-packages/zim/plugins/linesorter.py", line 57, in sort_selected_lines
    MessageDialog(self.ui,
AttributeError: 'MainWindowExtension' object has no attribute 'ui'

[Beth (beth-arronaz)]

I get this on both Windows and Linux, on different machines.