sugar: traceback when self._home_activity is None

[godiard]

We see this error in the logs:

  File "/usr/lib/python2.7/site-packages/sugar3/graphics/palettewindow.py", line 1302, in __enter_notify_event_cb
    self.notify_mouse_enter()
  File "/usr/lib/python2.7/site-packages/sugar3/graphics/palettewindow.py", line 977, in notify_mouse_enter
    self._ensure_palette_exists()
  File "/usr/lib/python2.7/site-packages/sugar3/graphics/palettewindow.py", line 972, in _ensure_palette_exists
    palette = self.parent.create_palette()
  File "/usr/lib/python2.7/site-packages/jarabe/desktop/favoritesview.py", line 607, in create_palette
    if self._home_activity.is_journal():

NoneType do not have is_journal() method

Looking at the code in the class CurrentActivityIcon, all the other uses of self._home_activity check if is None before use it.

[Gonzalo Odiard]

CurrentActivityIcon need check if _home_activity is None - Fixes #4725

Signed-off-by: Gonzalo Odiard <godiard@…>

Changeset: 8feab25a480427e31ffe7a8ab61a0ab98458f0c1