Record.get_eval must return only loaded values and validate only fields

Domain inversion should not have fields that are not loaded otherwise the
inversion could be wrong.

issue2865
review583003
(transplanted from 4d2bd7127a51862ab1293e8cdc4cf9f8bf217945)

tryton/common/domain_inversion.py

@@ -53,11 +53,11 @@ def eval_leaf(part, context, boolop=operator.and_):
         # In the case where the leaf concerns a m2o then having a value in the
         # evaluation context is deemed suffisant
         return bool(context.get(field.split('.')[0]))
-    if operand == '=' and not context[field] and boolop == operator.and_:
+    if operand == '=' and not context.get(field) and boolop == operator.and_:
         # We should consider that other domain inversion will set a correct
         # value to this field
         return True
-    context_field = context[field]
+    context_field = context.get(field)
     if isinstance(context_field, datetime.date) and not value:
         if isinstance(context_field, datetime.datetime):
             value = datetime.datetime.min

tryton/gui/window/view_form/model/record.py

@@ -249,6 +249,8 @@ class Record(SignalEvent):
             self._check_load()
         value = {}
         for name, field in self.group.fields.iteritems():
+            if name not in self._loaded and self.id >= 0:
+                continue
             value[name] = field.get_eval(self, check_load=check_load)
         value['id'] = self.id
         return value
@@ -448,7 +450,7 @@ class Record(SignalEvent):
         else:
             for field in fields:
                 self[field]
-        self.validate([])
+        self.validate(fields or [])
 
     def expr_eval(self, expr, check_load=False):
         if not isinstance(expr, basestring):