diff --git a/core/lib/Drupal/Core/Url.php b/core/lib/Drupal/Core/Url.php
index 9ea38b2..0703413 100644
--- a/core/lib/Drupal/Core/Url.php
+++ b/core/lib/Drupal/Core/Url.php
@@ -203,7 +203,7 @@ public static function fromRoute($route_name, $route_parameters = array(), $opti
    * @see static::fromRoute()
    */
   public static function fromUri($uri, $options = array()) {
-    if (!parse_url($uri, PHP_URL_SCHEME)) {
+    if ($uri != 'base://'  && !parse_url($uri, PHP_URL_SCHEME)) {
       throw new \InvalidArgumentException(String::format('The URI "@uri" is invalid. You must use a valid URI scheme. Use base:// for a path, e.g., to a Drupal file that needs the base path. Do not use this for internal paths controlled by Drupal.', ['@uri' => $uri]));
     }
 
diff --git a/core/modules/link/src/Plugin/Field/FieldWidget/LinkWidget.php b/core/modules/link/src/Plugin/Field/FieldWidget/LinkWidget.php
index 802c0ab..112231a 100644
--- a/core/modules/link/src/Plugin/Field/FieldWidget/LinkWidget.php
+++ b/core/modules/link/src/Plugin/Field/FieldWidget/LinkWidget.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\link\Plugin\Field\FieldWidget;
 
+use Drupal\Component\Utility\Unicode;
 use Drupal\Component\Utility\UrlHelper;
 use Drupal\Core\Field\FieldItemListInterface;
 use Drupal\Core\Field\WidgetBase;
@@ -47,7 +48,8 @@ public function formElement(FieldItemListInterface $items, $delta, array $elemen
     if (isset($items[$delta]->url)) {
       if ($url = \Drupal::pathValidator()->getUrlIfValid($items[$delta]->url)) {
         $url->setOptions($items[$delta]->options);
-        $default_url_value = ltrim($url->toString(), '/');
+        $url_string = $url->toString();
+        $default_url_value = $url->isRouted() ?  Unicode::substr($url_string, strlen(base_path())) : $url_string;
       }
     }
     $element['url'] = array(
diff --git a/core/modules/shortcut/src/Tests/ShortcutLinksTest.php b/core/modules/shortcut/src/Tests/ShortcutLinksTest.php
index fb484eb..1d9d047 100644
--- a/core/modules/shortcut/src/Tests/ShortcutLinksTest.php
+++ b/core/modules/shortcut/src/Tests/ShortcutLinksTest.php
@@ -8,6 +8,7 @@
 namespace Drupal\shortcut\Tests;
 
 use Drupal\Component\Utility\String;
+use Drupal\Core\Url;
 use Drupal\shortcut\Entity\Shortcut;
 use Drupal\shortcut\Entity\ShortcutSet;
 
@@ -61,7 +62,7 @@ public function testShortcutLinkAdd() {
       $saved_set = ShortcutSet::load($set->id());
       $paths = $this->getShortcutInformation($saved_set, 'link');
       $test['path'] = $test['path'] != '<front>' ? $test['path'] : '';
-      $this->assertTrue(in_array($test['path'], $paths), 'Shortcut created: ' . $test['path']);
+      $this->assertTrue(in_array(Url::fromUri('base://' . $test['path']), $paths), 'Shortcut created: ' . $test['path']);
       $this->assertLink($title, 0, String::format('Shortcut link %url found on the page.', ['%url' => $test['path']]));
     }
     $saved_set = ShortcutSet::load($set->id());
@@ -87,7 +88,7 @@ public function testShortcutLinkAdd() {
     ];
     $this->drupalPostForm('admin/config/user-interface/shortcut/manage/' . $set->id() . '/add-link', $form_data, t('Save'));
     $this->assertResponse(200);
-    $this->assertRaw(t('The URL admin is not valid.'));
+    $this->assertRaw(String::format('The URL %url is not valid.', ['%url' => 'admin']));
 
     $form_data = [
       'title[0][value]' => $title,
@@ -159,7 +160,7 @@ public function ptestShortcutLinkChangePath() {
     $this->drupalPostForm('admin/config/user-interface/shortcut/link/' . $shortcut->id(), array('title[0][value]' => $shortcut->getTitle(), 'link[0][url]' => $new_link_path), t('Save'));
     $saved_set = ShortcutSet::load($set->id());
     $paths = $this->getShortcutInformation($saved_set, 'link');
-    $this->assertTrue(in_array($new_link_path, $paths), 'Shortcut path changed: ' . $new_link_path);
+    $this->assertTrue(in_array(Url::fromUri('base://' . $new_link_path), $paths), 'Shortcut path changed: ' . $new_link_path);
     $this->assertLinkByHref($new_link_path, 0, 'Shortcut with new path appears on the page.');
   }
 
diff --git a/core/modules/shortcut/src/Tests/ShortcutTestBase.php b/core/modules/shortcut/src/Tests/ShortcutTestBase.php
index 4126b99..34abfe2 100644
--- a/core/modules/shortcut/src/Tests/ShortcutTestBase.php
+++ b/core/modules/shortcut/src/Tests/ShortcutTestBase.php
@@ -122,7 +122,7 @@ function getShortcutInformation(ShortcutSetInterface $set, $key) {
     \Drupal::entityManager()->getStorage('shortcut')->resetCache();
     foreach ($set->getShortcuts() as $shortcut) {
       if ($key == 'link') {
-        $info[] = ltrim($shortcut->getUrl()->toString(), '/');
+        $info[] = $shortcut->getUrl()->toString();
       }
       else {
         $info[] = $shortcut->{$key}->value;