[FIX] web: Error on invalid date format on date field input

Steps to reproduce the bug:

- Go to any field Date
- Enter wrong date

Bug:
A traceback was raised.

Now a warning is raised and the wrong value is removed.

opw:1974747

closes odoo/odoo#33362

Signed-off-by: Simon Goffin (sig) <sig@openerp.com>

addons/web/static/src/js/widgets/date_picker.js

@@ -13,6 +13,7 @@ var DateWidget = Widget.extend({
     type_of_date: "date",
     events: {
         'change.datetimepicker': 'changeDatetime',
+        'error.datetimepicker': 'errorDatetime',
         'change .o_datepicker_input': 'changeDatetime',
         'input input': '_onInput',
         'keydown': '_onKeydown',
@@ -103,6 +104,15 @@ var DateWidget = Widget.extend({
             }
         }
     },
+    /**
+     * Library clears the wrong date format so just ignore error
+     */
+    errorDatetime: function (e) {
+        if (!e.date.isValid()){
+            this.do_warn(_t("Error"), e.date.toString());
+        }
+        return false;
+    },
     /**
      * Focuses the datepicker input. This function must be called in order to
      * prevent 'input' events triggered by the lib to bubble up, and to cause

addons/web/static/tests/fields/basic_fields_tests.js

@@ -2667,6 +2667,25 @@ QUnit.module('basic_fields', {
         form.destroy();
     });
 
+    QUnit.test('date field should remove the date  if the date is not valid', function (assert) {
+        assert.expect(1);
+
+        var form = createView({
+            View: FormView,
+            model: 'partner',
+            data: this.data,
+            arch: '<form string="Partners"><field name="date"/></form>',
+            res_id: 4,
+        });
+        // switch to edit mode
+        form.$buttons.find('.o_form_button_edit').click();
+        // set an invalid date
+        var $input = form.$('.o_field_widget[name=date] input');
+        $input.val('mmmh').trigger('change');
+        assert.strictEqual($input.text(), "", "The date field should be empty");
+        form.destroy();
+    });
+
     QUnit.test('date field value should not set on first click', function (assert) {
         assert.expect(2);