Journal model: traceback

[manuq]

This may be similar to #3888 .

Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/sugar3/graphics/palettewindow.py", line 1442, in __long_pressed_event_cb
    self.notify_right_click()
  File "/usr/lib/python2.7/site-packages/sugar3/graphics/palettewindow.py", line 967, in notify_right_click
    self._ensure_palette_exists()
  File "/usr/lib/python2.7/site-packages/sugar3/graphics/palettewindow.py", line 955, in _ensure_palette_exists
    palette = self.parent.create_palette()
  File "/usr/lib/python2.7/site-packages/jarabe/journal/listview.py", line 641, in create_palette
    metadata = tree_model.get_metadata(self.props.palette_invoker.path)
  File "/usr/lib/python2.7/site-packages/jarabe/journal/listmodel.py", line 103, in get_metadata
    return model.get(self[path][ListModel.COLUMN_UID])
  File "/usr/lib/python2.7/site-packages/gi/overrides/Gtk.py", line 782, in __getitem__
    aiter = self._getiter(key)
  File "/usr/lib/python2.7/site-packages/gi/overrides/Gtk.py", line 776, in _getiter
    aiter = self.get_iter(key)
  File "/usr/lib/python2.7/site-packages/gi/overrides/Gtk.py", line 798, in get_iter
    path = TreePath(path)
  File "/usr/lib/python2.7/site-packages/gi/overrides/Gtk.py", line 1209, in __new__
    if len(path) == 0:
TypeError: object of type 'NoneType' has no len()

[erikos]

From my testing this happens when a long press on an activity icon in the Journal list view does not reveal the Palette. I had this issue now two times. In the same Sugar session I could use the long-press on activity icons in the Journal fine later.

As I have seen the issue only in those cases, I will remove the 'regression' keywords.

[godiard]

Closed as duplicated of #4717