Stop loading fields definition already known by the field

sao/src/model.js

@@ -2202,23 +2202,45 @@
                 for (const val of value) {
                     for (const fieldname in val) {
                         if (!(fieldname in group.model.fields) &&
-                                (!~fieldname.indexOf('.'))) {
+                                (!~fieldname.indexOf('.')) &&
+                                (!fieldname.startsWith('_'))) {
                             field_names.add(fieldname);
                         }
                     }
                 }
-                if (field_names.size) {
+                var attr_fields = Object.values(this.description.views || {})
+                    .map(v => v.fields)
+                    .reduce((acc, elem) => {
+                        for (const field in elem) {
+                            acc[field] = elem[field];
+                        }
+                        return acc;
+                    }, {});
+                var fields = {};
+                for (const n of field_names) {
+                    if (n in attr_fields) {
+                        fields[n] = attr_fields[n];
+                    }
+                }
+
+                var to_fetch = Array.from(field_names).filter(k => !(k in attr_fields));
+                if (to_fetch.length) {
                     var args = {
                         'method': 'model.' + this.description.relation +
                             '.fields_get',
-                        'params': [Array.from(field_names), context]
+                        'params': [to_fetch, context]
                     };
-                    var fields;
                     try {
-                        fields = Sao.rpc(args, record.model.session, false);
+                        var rpc_fields = Sao.rpc(
+                            args, record.model.session, false);
+                        for (const [key, value] of Object.entries(rpc_fields)) {
+                            fields[key] = value;
+                        }
                     } catch (e) {
                         return;
                     }
+                }
+                if (!jQuery.isEmptyObject(fields)) {
                     group.add_fields(fields);
                 }
             }

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

@@ -2,9 +2,11 @@
 # this repository contains the full copyright notices and license terms.
 import datetime
 import decimal
+import functools
 import locale
 import logging
 import math
+import operator
 import os
 from decimal import Decimal
 from itertools import chain
@@ -712,13 +714,25 @@ class O2MField(Field):
         if mode == 'list values':
             context = self.get_context(record)
             field_names = set(f for v in value for f in v
-                if f not in group.fields and '.' not in f)
-            if field_names:
+                if (f not in group.fields
+                    and '.' not in f
+                    and ':' not in f
+                    and not f.startswith('_')))
+            attr_fields = functools.reduce(
+                operator.or_,
+                (v['fields'] for v in self.attrs.get('views', {}).values()),
+                {})
+            fields = {n: attr_fields[n]
+                for n in field_names
+                if n in attr_fields}
+            if to_fetch := (field_names - attr_fields.keys()):
                 try:
-                    fields = RPCExecute('model', self.attrs['relation'],
-                        'fields_get', list(field_names), context=context)
+                    fields |= RPCExecute('model', self.attrs['relation'],
+                        'fields_get', list(to_fetch), context=context)
                 except RPCException:
                     return
+
+            if fields:
                 group.load_fields(fields)
 
         if mode == 'list ids':

trytond/trytond/model/modelview.py

@@ -507,6 +507,8 @@ class ModelView(Model):
             tree, encoding='utf-8', pretty_print=False).decode('utf-8')
         # Do not call fields_def without fields as it returns all fields
         if fields_def:
+            # Prevent clients calling fields_view_get to get 'id' definition
+            fields_def.setdefault('id', {'name': 'id'})
             fields2 = cls.fields_get(list(fields_def.keys()), level=level)
         else:
             fields2 = {}

trytond/trytond/tests/test_modelview.py

@@ -611,7 +611,7 @@ class ModelView(unittest.TestCase):
 
         fields = DependsDepends.fields_view_get(view_type='form')['fields']
 
-        self.assertEqual(fields.keys(), {'foo', 'bar', 'baz'})
+        self.assertEqual(fields.keys(), {'id', 'foo', 'bar', 'baz'})
 
     @with_transaction(context={'_check_access': True})
     def test_button_depends_access(self):