[FIX] web: avoid freezing the browser when scrolling to undefined

Before this commit the browser did freeze if scrollTo(undefined) was
called. This happened because our "closestScrollable"'s jQuery addition
entered an infinite recursive exploration of .parent() elements starting
from $(undefined).

After this commit such wrong calls to scrollTo() will not freeze the
browser anymore but crash instead. The closestScrollable function was
also made more robust and return an empty element instead of looping.

task-2630257

X-original-commit: d1cda0f3ebb942ad58273db36692f28fa8a3b197
Co-authored-by: qsm-odoo <qsm@odoo.com>

addons/web/static/src/legacy/js/core/dom.js

@@ -157,10 +157,10 @@ var dom = {
         }
     },
     /**
-     * @return {HTMLElement}
+     * @return {HTMLElement|null}
      */
     closestScrollable(el) {
-        return $(el).closestScrollable()[0];
+        return $(el).closestScrollable()[0] || null;
     },
     /**
      * @param {HTMLElement} el
@@ -549,6 +549,9 @@ var dom = {
      * @return {Promise}
      */
     scrollTo(el, options = {}) {
+        if (!el) {
+            throw new Error("The scrollTo function was called without any given element");
+        }
         const $el = $(el);
         const $scrollable = options.$scrollable || $el.parent().closestScrollable();
         // If $scrollable and $el are not in the same document, we can safely

addons/web/static/src/legacy/js/libs/jquery.js

@@ -128,6 +128,10 @@ $.fn.extend({
     closestScrollable() {
         let $el = this;
         while ($el[0] !== document.scrollingElement) {
+            // Avoid infinite loop.
+            if (!$el.length) {
+                return $();
+            }
             if ($el.isScrollable()) {
                 return $el;
             }