[FIX] web: x2m in x2m with different fields in different views

Use case: a x2m (ex: attribute values) displayed in a x2m (ex: attributes on
product) using different fields in different views (ex: tags in product form view
and list in product attribute form view). When opening the x2m record (in a
wizard) then going back on the form view, the tags are empty because the
`display_name` value has been lost when fetching x2m for the second time.

In this case, the list `fieldsInfo` needs to be updated with the existing
(default for tags) one so all the fields will be correctly loaded.

Task 1916891

closes odoo/odoo#29598

1 files changed, 15 insertions, 0 deletions

diff --git a/addons/web/static/src/js/views/basic/basic_view.js b/addons/web/static/src/js/views/basic/basic_view.js
index cdb1cc05290..d966129b547 100644
--- a/addons/web/static/src/js/views/basic/basic_view.js
+++ b/addons/web/static/src/js/views/basic/basic_view.js
@@ -107,6 +107,21 @@ var BasicView = AbstractView.extend({
                             if (_.difference(fieldViewTypes, recordViewTypes).length) {
                                 fieldNames.push(name);
                             }
+
+                            if (record.data[name].viewType === 'default') {
+                                // Use case: x2many (tags) in x2many list views
+                                // When opening the x2many record form view, the
+                                // x2many will be reloaded but it may not have
+                                // the same fields (ex: tags in list and list in
+                                // form) so we need to merge the fieldsInfo to
+                                // avoid losing the initial fields (display_name)
+                                var defaultFieldInfo = record.data[name].fieldsInfo.default;
+                                _.each(fieldViews, function (fieldView) {
+                                    _.each(fieldView.fieldsInfo, function (x2mFieldInfo) {
+                                        _.defaults(x2mFieldInfo, defaultFieldInfo);
+                                    });
+                                });
+                            }
                         }
                     }
                     // Many2one: context is not the same between the different views