Fix fall-back date format

The date_format must come from screen context as fall-back.
The date_format must be set on all actions context

issue4892
review19351002

tryton/action/main.py

@@ -84,6 +84,11 @@ class Action(object):
     def _exec_action(action, data=None, context=None):
         if context is None:
             context = {}
+        else:
+            context = context.copy()
+        if 'date_format' not in context:
+            context['date_format'] = rpc.CONTEXT.get(
+                'locale', {}).get('date', '%x')
         if data is None:
             data = {}
         else:
@@ -114,9 +119,6 @@ class Action(object):
             ctx.update(action_ctx)
             ctx.update(context)
             action_ctx.update(context)
-            if 'date_format' not in action_ctx:
-                action_ctx['date_format'] = rpc.CONTEXT.get(
-                    'locale', {}).get('date', '%x')
 
             ctx['context'] = ctx
             decoder = PYSONDecoder(ctx)

tryton/gui/window/view_form/view/form_gtk/calendar.py

@@ -59,7 +59,7 @@ class Date(Widget):
         if field and record:
             format_ = field.date_format(record)
         else:
-            format_ = '%x'
+            format_ = self.view.screen.context.get('date_format', '%x')
         self.entry.props.format = format_
 
     def display(self, record, field):
@@ -126,7 +126,7 @@ class DateTime(Date):
             date_format = field.date_format(record)
             time_format = field.time_format(record)
         else:
-            date_format = '%x'
+            date_format = self.view.screen.context.get('date_format', '%x')
             time_format = '%X'
         self.entry.props.date_format = date_format
         self.entry.props.time_format = time_format