[FIX] mass_mailing: save transpiled html without affecting body_arch

Since the introduction of Odoo Editor, `field_html`'s `_getValue` uses
`wysiwyg.getValue`. This conflicts with the mechanism of `mass_mailing`
which modifies the html of the editable area in place to save an
"e-mailable" version on the `body_html` field, then relies on
`_getValue` to reset the original html (`body_arch`).
This ensures the field has a value before modifying the html in place,
so we can manually restore it instead of relying on a side effect of the
old behavior of `_getValue`.

Part-of: odoo/odoo#75901

addons/mass_mailing/static/src/js/mass_mailing_widget.js

@@ -65,6 +65,7 @@ var MassMailingFieldHtml = FieldHtml.extend({
         }
         return this.wysiwyg.saveModifiedImages(this.$content).then(function () {
             self._isDirty = self.wysiwyg.isDirty();
+            self._doAction();
 
             convertInline.attachmentThumbnailToLinkImg($editable);
             convertInline.fontToImg($editable);
@@ -84,6 +85,7 @@ var MassMailingFieldHtml = FieldHtml.extend({
                 changes: _.object([fieldName], [self._unWrap($editable.html())])
             });
 
+            $editable.html(self.value);
             if (self._isDirty && self.mode === 'edit') {
                 return self._doAction();
             }

addons/mass_mailing/static/src/js/tours/mass_mailing_editor_tour.js

@@ -0,0 +1,28 @@
+odoo.define('mass_mailing.mass_mailing_editor_tour', function (require) {
+    "use strict";
+
+    var tour = require('web_tour.tour');
+
+    tour.register('mass_mailing_editor_tour', {
+        url: '/web',
+        test: true,
+    }, [tour.stepUtils.showAppsMenuItem(), {
+        trigger: '.o_app[data-menu-xmlid="mass_mailing.mass_mailing_menu_root"]',
+    }, {
+        trigger: 'button.o_list_button_add',
+    }, {
+        trigger: 'input[name="subject"]',
+        run: 'text Test',
+    }, {
+        trigger: 'div[name="contact_list_ids"] .o_input_dropdown > input[type="text"]',
+    }, {
+        trigger: 'li.ui-menu-item',
+    }, {
+        trigger: 'iframe #default',
+        run: () => $('iframe').contents().find('o_editable').html('<p><br/></p>'),
+    }, {
+        trigger: 'button.o_form_button_save',
+    }, {
+        trigger: 'iframe.o_readonly',
+    }]);
+});

addons/mass_mailing/tests/__init__.py

@@ -7,3 +7,4 @@ from . import test_mailing_internals
 from . import test_mailing_list
 from . import test_mailing_controllers
 from . import test_mailing_mailing_schedule_date
+from . import test_mailing_ui

addons/mass_mailing/tests/test_mailing_ui.py

@@ -0,0 +1,23 @@
+# -*- coding: utf-8 -*-
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+
+import odoo.tests
+from odoo.addons.base.tests.common import HttpCaseWithUserDemo
+
+
+@odoo.tests.tagged('-at_install', 'post_install')
+class TestUi(HttpCaseWithUserDemo):
+    def setUp(self):
+        super().setUp()
+        self.user_demo.groups_id |= self.env.ref('mass_mailing.group_mass_mailing_user')
+        self.user_demo.groups_id |= self.env.ref('mail.group_mail_template_editor')
+
+    def test_01_mass_mailing_editor_tour(self):
+        self.start_tour("/web", 'mass_mailing_editor_tour', login="demo")
+        mail = self.env['mailing.mailing'].search([('subject', '=', 'Test')])[0]
+        # The tour created and saved an email. The edited version should be
+        # saved in body_arch, and its transpiled version (see convert_inline)
+        # for email client compatibility should be saved in body_html. This
+        # ensures both fields have different values.
+        self.assertEqual(mail.body_arch, '<p><br></p>')
+        self.assertEqual(mail.body_html, '<p style="margin:0px 0 1rem 0;"><br></p>')

addons/web_editor/static/src/js/backend/convert_inline.js

@@ -24,7 +24,7 @@ function getMatchedCSSRules(a) {
             try {
                 rules = sheets[i].rules || sheets[i].cssRules;
             } catch (e) {
-                console.warn("Can't read the css rules of: " + sheets[i].href, e);
+                console.log("Can't read the css rules of: " + sheets[i].href, e);
                 continue;
             }
             if (rules) {