[FIX] web_editor: fix race condition in grid_layout tour

When trying to replace an image with the media dialog, there is first a
click on the image, which activates the options of the image, and then
a double-click, opening the media dialog to choose the new image.
However, the media dialog does not wait for the image options to be
completely initialized before opening.

This behaviour is in general not problematic but if it happens quickly
enough, in a tour for example, it might cause a traceback. This happens
because the renderings (in `_renderCustomXML`) of the image before and
after replacing it happen too closely, making the first one lose the
reference to the image parent.

This commit fixes this issue by waiting for the options to be fully
initialized before opening the media dialog, that is, by adding an
empty action in the mutex and waiting for it to complete.

runbot-10692

closes odoo/odoo#108738

X-original-commit: 7667ba149aaf179f430615c4aba4b963d1d167c6
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>

addons/web_editor/static/src/js/editor/snippets.editor.js

@@ -2123,6 +2123,14 @@ var SnippetsMenu = Widget.extend({
         // the invisible DOM list if needed.
         await this._updateInvisibleDOM();
     },
+    /**
+     * Public implementation of _execWithLoadingEffect.
+     *
+     * @see this._execWithLoadingEffect for parameters
+     */
+    execWithLoadingEffect(action, contentLoading = true, delay = 500) {
+        return this._execWithLoadingEffect(...arguments);
+    },
 
     //--------------------------------------------------------------------------
     // Private

addons/web_editor/static/src/js/wysiwyg/wysiwyg.js

@@ -308,7 +308,14 @@ const Wysiwyg = Widget.extend({
                 $el.selectElement();
 
                 if (!$el.parent().hasClass('o_stars')) {
-                    self.openMediaDialog(params);
+                    // Waiting for all the options to be initialized before
+                    // opening the media dialog and only if the media has not
+                    // been deleted in the meantime.
+                    self.waitForEmptyMutexAction().then(() => {
+                        if ($el[0].parentElement) {
+                            self.openMediaDialog(params);
+                        }
+                    });
                 }
             }
         });
@@ -1422,6 +1429,18 @@ const Wysiwyg = Widget.extend({
     getInSelection(selector) {
         return getInSelection(this.odooEditor.document, selector);
     },
+    /**
+     * Adds an empty action in the mutex. Can be used to wait for some options
+     * to be initialized before doing something else.
+     *
+     * @returns {Promise}
+     */
+    waitForEmptyMutexAction() {
+        if (this.snippetsMenu) {
+            return this.snippetsMenu.execWithLoadingEffect(() => null, false);
+        }
+        return Promise.resolve();
+    },
 
     //--------------------------------------------------------------------------
     // Private