Problem with date field and sqlite
When doing some tests on product_cost_history with an sqlite database, gtk client freeze when doing a relate from variant to product_cost_price (with some prices values)
AttributeError: 'str' object has no attribute 'strftime'
ERROR:tryton.common.common: File "/home/mrichez/Workspace/tryton/issues/add_picking_state/tryton/tryton/gui/window/view_form/view/list_gtk/widget.py", line 60, in wrapper
return func(self, *args, **kwargs)
File "/home/mrichez/Workspace/tryton/issues/add_picking_state/tryton/tryton/gui/window/view_form/view/list_gtk/widget.py", line 392, in setter
super(Date, self).setter(column, cell, store, iter_, user_data)
File "/home/mrichez/Workspace/tryton/issues/add_picking_state/tryton/tryton/gui/window/view_form/view/list_gtk/widget.py", line 60, in wrapper
return func(self, *args, **kwargs)
File "/home/mrichez/Workspace/tryton/issues/add_picking_state/tryton/tryton/gui/window/view_form/view/list_gtk/widget.py", line 105, in wrapper
func(self, column, cell, store, iter_, user_data)
File "/home/mrichez/Workspace/tryton/issues/add_picking_state/tryton/tryton/gui/window/view_form/view/list_gtk/widget.py", line 239, in setter
text = self.get_textual_value(record)
File "/home/mrichez/Workspace/tryton/issues/add_picking_state/tryton/tryton/gui/window/view_form/view/list_gtk/widget.py", line 405, in get_textual_value
return value.strftime(self.renderer.props.format)