[FIX] web: handle m2o whose comodel name field is an m2o

This is a weird situation, but the python handles it. Let's assume
a many2one field F1 on model M1 with comodel M2, and on M2 the name
field (which is the _rec_name) being itself a many2one, and the
following scenario:
 - create a new record for M1
 - for field F1, select 'Create and Edit': it opens a form view for
   M2 in a dialog
 - type something in F2 input, and click 'Quick create'
 - save the dialog

Before this rev., the value of F1 was [object Object]. Now, the new
value is properly displayed.

OPW 2091106

closes odoo/odoo#40549

X-original-commit: 5a04ea848abf50b1fb1f9893d1fcd98013bc025d
Signed-off-by: Aaron Bohy (aab) <aab@odoo.com>

addons/web/static/src/js/fields/field_utils.js

@@ -252,7 +252,7 @@ function formatInteger(value, field, options) {
  * return an empty string.  Note that it accepts two types of input parameters:
  * an array, in that case we assume that the many2one value is of the form
  * [id, nameget], and we return the nameget, or it can be an object, and in that
- * case, we assume that it is a record from a BasicModel.
+ * case, we assume that it is a record datapoint from a BasicModel.
  *
  * @param {Array|Object|false} value
  * @param {Object} [field]
@@ -262,7 +262,18 @@ function formatInteger(value, field, options) {
  * @returns {string}
  */
 function formatMany2one(value, field, options) {
-    value = value && (_.isArray(value) ? value[1] : value.data.display_name) || '';
+    if (!value) {
+        value = '';
+    } else if (_.isArray(value)) {
+        // value is a pair [id, nameget]
+        value = value[1];
+    } else {
+        // value is a datapoint, so we read its display_name field, which
+        // may in turn be a datapoint (if the name field is a many2one)
+        while (value.data) {
+            value = value.data.display_name || '';
+        }
+    }
     if (options && options.escape) {
         value = _.escape(value);
     }

addons/web/static/tests/fields/relational_fields/field_many2one_tests.js

@@ -2,7 +2,6 @@ odoo.define('web.field_many_to_one_tests', function (require) {
 "use strict";
 
 var BasicModel = require('web.BasicModel');
-var concurrency = require('web.concurrency');
 var FormView = require('web.FormView');
 var ListView = require('web.ListView');
 var relationalFields = require('web.relational_fields');
@@ -790,6 +789,41 @@ QUnit.module('fields', {}, function () {
             form.destroy();
         });
 
+        QUnit.test('many2one with co-model whose name field is a many2one', async function (assert) {
+            assert.expect(4);
+
+            this.data.product.fields.name = {
+                string: 'User Name',
+                type: 'many2one',
+                relation: 'user',
+            };
+
+            const form = await createView({
+                View: FormView,
+                model: 'partner',
+                data: this.data,
+                arch: '<form><field name="product_id"/></form>',
+                archs: {
+                    'product,false,form': '<form><field name="name"/></form>',
+                },
+            });
+
+            // click on 'Create and Edit' in m2o dropdown
+            await testUtils.fields.many2one.clickOpenDropdown('product_id');
+            await testUtils.fields.many2one.clickItem('product_id', 'Create and Edit');
+            assert.containsOnce(document.body, '.modal .o_form_view');
+
+            // quick create 'new value'
+            await testUtils.fields.many2one.searchAndClickItem('name', {search: 'new value'});
+            assert.strictEqual($('.modal .o_field_many2one input').val(), 'new value');
+
+            await testUtils.dom.click($('.modal .modal-footer .btn-primary')); // save in modal
+            assert.containsNone(document.body, '.modal .o_form_view');
+            assert.strictEqual(form.$('.o_field_many2one input').val(), 'new value');
+
+            form.destroy();
+        });
+
         QUnit.test('many2one searches with correct value', async function (assert) {
             assert.expect(6);