software-properties-gtk crashed with AttributeError in toggle_source_use(): 'NoneType' object has no attribute 'disabled'

Status changed to 'Confirmed' because the bug affects multiple users.

Could you please attach your /etc/apt/sources.list and the files in /etc/apt/sources.list.d ?

This may actually be a dupe (or different sympthom) of #820028 that got fixed with:

software-properties (0.81.10) oneiric; urgency=low

  * softwareproperties/dbus/SoftwarePropertiesDBus.py, tests/test_dbus.py:
    - fix crash when there are unicode comments in the sources.list
      file (LP: #820028). Dbus always sends us a dbus.String which is
      type unicode, but python-apt expects utf8 encoded str

 -- Michael Vogt <email address hidden> Mon, 10 Oct 2011 10:55:45 +0200

Could you try if that's still an issue?

Reproduced this, with the following steps:
1. Add PPA with add-apt-repository (adds both deb and deb-src)
2. Remove PPA with add-apt-repository --remove (only removes deb entry , deb-src is left there, see bug #838507)
3. Open Software sources and try to disable or remove the deb-src entry left there

Expected result:
The deb-src entry is removed
What happens:
Nothing, but the trace attached is written to stdout.

Same here, 11.10 and Gnome Shell.
Some other infos:

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/softwareproperties/gtk/SoftwarePropertiesGtk.py", line 649, in on_isv_source_toggled
    self.backend.ToggleSourceUse(str(source_entry))
  File "/usr/lib/python2.7/dist-packages/dbus/proxies.py", line 143, in __call__
    **keywords)
  File "/usr/lib/python2.7/dist-packages/dbus/connection.py", line 630, in call_blocking
    message, timeout)
dbus.exceptions.DBusException: org.freedesktop.DBus.Python.AttributeError: Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/dbus/service.py", line 702, in _message_cb
    retval = candidate_method(self, *args, **keywords)
  File "/usr/lib/python2.7/dist-packages/softwareproperties/dbus/SoftwarePropertiesDBus.py", line 156, in ToggleSourceUse
    self.toggle_source_use(source.encode("utf-8"))
  File "/usr/lib/python2.7/dist-packages/softwareproperties/SoftwareProperties.py", line 433, in toggle_source_use
    source.disabled = not source.disabled
AttributeError: 'NoneType' object has no attribute 'disabled'

All I can add is that it occurred on bootup.

On boot up too

any modification triggers it. I added the ppa for wine and tried to edit the distribution from placid to oneric, and it misbehaved.

Happened in 12.04 (latest updates) after Unity booted up.

Cannot remove the ticks on the left of the sources (added with add-apt-repository), then crash.

Can reproduce.

So this seems to happen when starting software-properties-dbus, then adding a new apt source; the D-BUS backend does not know about it yet, but the frontend does, so the backend doesn't find the Source for the corresponding string when trying to disable it.

This bug was fixed in the package software-properties - 0.82.5

---------------
software-properties (0.82.5) precise; urgency=low

  * softwareproperties/gtk/SoftwarePropertiesGtk.py: Drop duplicate definition
    of on_treeview_sources_cursor_changed().
  * softwareproperties/gtk/SoftwarePropertiesGtk.py: Fix crash when closing
    the application with the window title bar button. (LP: #911834)
  * add-apt-repository: Intercept ValueError in addition to URLError, as this
    is the error thrown when trying to decode invalid JSON (which happens on
    404 pages etc.). (LP: #861258)
  * softwareproperties/SoftwareProperties.py, _find_source_from_string():
    Reload the sources list before searching, as it might have changed while
    the D-BUS backend was running. (LP: #854818, #820150)
  * softwareproperties/gtk/SoftwarePropertiesGtk.py: Add missing argument to
    menu popup() call. (LP: #815236)
 -- Martin Pitt <email address hidden> Wed, 07 Mar 2012 10:14:52 +0100

It is still there on oneiric.

I reproduced this bug with software-properties 0.82.7 on precise and I was redirect here by the automatic bug reporting.