[FIX] web: list: multi edition: force write same value

Let's assume an editable list view with a many2one field and 2
records: the first one has value 1, the second value 2. The user
selects all records and wants to set their many2one to value 1. It
edits the first one, sets 1 and validates the confirm dialog.

Before this rev., it didn't save anything because the 'reference'
record (the one used to edit), didn't actually changed, as we reset
the same value.

This rev. forces the write the new value on all selected records in
that case.

Task 2068280

2 files changed, 10 insertions, 3 deletions

diff --git a/addons/web/static/src/js/views/list/list_controller.js b/addons/web/static/src/js/views/list/list_controller.js
index dc26a750eb4..cf911ef5398 100644
--- a/addons/web/static/src/js/views/list/list_controller.js
+++ b/addons/web/static/src/js/views/list/list_controller.js
@@ -457,6 +457,7 @@ var ListController = BasicController.extend({
      */
     _saveMultipleRecords: function (recordId, node, changes) {
         var self = this;
+        var fieldName = Object.keys(changes)[0];
         var value = Object.values(changes)[0];
         var recordIds = _.union([recordId], this.selectedRecords);
         var validRecordIds = recordIds.reduce(function (result, nextRecordId) {
@@ -487,7 +488,7 @@ var ListController = BasicController.extend({
                 }
                 Dialog.confirm(this, message, {
                     confirm_callback: () => {
-                        this.model.saveRecords(recordId, validRecordIds)
+                        this.model.saveRecords(recordId, validRecordIds, fieldName)
                             .then(() => {
                                 this._updateButtons('readonly');
                                 const state = this.model.get(this.handle);
diff --git a/addons/web/static/src/js/views/list/list_model.js b/addons/web/static/src/js/views/list/list_model.js
index 900f3764b0e..65526346c8e 100644
--- a/addons/web/static/src/js/views/list/list_model.js
+++ b/addons/web/static/src/js/views/list/list_model.js
@@ -40,12 +40,18 @@ odoo.define('web.ListModel', function (require) {
          * @param {string} referenceRecordId the record datapoint used to
          *  generate the changes to apply to recordIds
          * @param {string[]} recordIds a list of record datapoint ids
+         * @param {string} fieldName the field to write
          */
-        saveRecords: function (referenceRecordId, recordIds) {
+        saveRecords: function (referenceRecordId, recordIds, fieldName) {
             var self = this;
             var referenceRecord = this.localData[referenceRecordId];
             var list = this.localData[referenceRecord.parentID];
-            var changes = this._generateChanges(referenceRecord, {});
+            // generate all record values to ensure that we'll write something
+            // (e.g. 2 records selected, edit a many2one in the first one, but
+            // reset same value, we still want to save this value on the other
+            // record)
+            var allChanges = this._generateChanges(referenceRecord, {changesOnly: false});
+            var changes = _.pick(allChanges, fieldName);
             var records = recordIds.map(function (recordId) {
                 return self.localData[recordId];
             });