diff -u b/core/modules/media_library/src/Form/AddFormBase.php b/core/modules/media_library/src/Form/AddFormBase.php
--- b/core/modules/media_library/src/Form/AddFormBase.php
+++ b/core/modules/media_library/src/Form/AddFormBase.php
@@ -126,6 +126,8 @@
     ];
 
     $form['#attributes']['class'][] = 'media-library-add-form';
+    $form['#attributes']['class'][] = 'js-media-library-add-form';
+
     $added_media = $form_state->get('media');
     if (empty($added_media)) {
       $form['#attributes']['class'][] = 'media-library-add-form--without-input';
@@ -142,8 +144,22 @@
         $form['media'][$delta] = $this->buildEntityFormElement($media, $form, $form_state, $delta);
       }
 
+      $form['selection'] = $this->buildSelection($form, $form_state);
       $form['actions'] = $this->buildActions($form, $form_state);
     }
+
+    // Allow the current selection to be set in a hidden field so the selection
+    // can be passed between different states of the form.
+    $form['current_selection'] = [
+      '#type' => 'hidden',
+      '#default_value' => '',
+      '#attributes' => [
+        'class' => [
+          'js-media-library-add-form-current-selection',
+        ],
+      ],
+    ];
+
     return $form;
   }
 
@@ -252,4 +268,65 @@
 
   /**
+   * Returns a render array containing the current selection.
+   *
+   * @param array $form
+   *   The complete form.
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   The current form state.
+   *
+   * @return array
+   *   A render array containing the current selection.
+   */
+  protected function buildSelection(array $form, FormStateInterface $form_state) {
+    $media_ids = array_filter(explode(',', $form_state->getValue('current_selection')));
+
+    if (!$media_ids) {
+      return [];
+    }
+
+    $media_items = $this->entityTypeManager->getStorage('media')->loadMultiple($media_ids);
+    $view_builder = $this->entityTypeManager->getViewBuilder('media');
+
+    $selection = [
+      '#type' => 'container',
+      '#attributes' => [
+        'class' => [
+          'media-library-add-form-selection',
+        ],
+      ],
+    ];
+
+    foreach ($media_items as $media_id => $media) {
+      $selection[$media_id] = [
+        '#type' => 'container',
+        '#attributes' => [
+          'class' => [
+            'media-library-item',
+            'js-media-library-item',
+            'js-click-to-select',
+          ],
+        ],
+        'select' => [
+          '#type' => 'container',
+          '#attributes' => [
+            'class' => [
+              'js-click-to-select-checkbox',
+            ],
+          ],
+          'select_checkbox' => [
+            '#type' => 'checkbox',
+            '#title' => $this->t('Select @name', ['@name' => $media->label()]),
+            '#title_display' => 'invisible',
+            '#return_value' => $media_id,
+          ],
+        ],
+        'rendered_entity' => $view_builder->view($media, 'media_library'),
+      ];
+    }
+
+    return $selection;
+  }
+
+  /**
    * Returns an array of supported actions for the form.
    *
@@ -458,10 +535,13 @@
       return $form;
     }
 
+    // Merge added and selected media.
+    $selected_media_ids = array_filter(explode(',', $form_state->getValue('current_selection')));
     $added_media = $form_state->get('media') ?: [];
-    $media_ids = array_map(function (MediaInterface $media) {
+    $added_media_ids = array_map(function (MediaInterface $media) {
       return $media->id();
     }, $added_media);
+    $media_ids = array_merge($selected_media_ids, $added_media_ids);
 
     // Pass the selection to the field widget based on the current widget ID.
     $opener_id = MediaLibraryState::fromRequest($this->getRequest())->getOpenerId();
diff -u b/core/modules/media_library/tests/src/FunctionalJavascript/MediaLibraryTest.php b/core/modules/media_library/tests/src/FunctionalJavascript/MediaLibraryTest.php
--- b/core/modules/media_library/tests/src/FunctionalJavascript/MediaLibraryTest.php
+++ b/core/modules/media_library/tests/src/FunctionalJavascript/MediaLibraryTest.php
@@ -593,10 +593,8 @@
     $assert_session->elementExists('css', '.media-library-open-button[href*="field_twin_media"]')->click();
     $assert_session->assertWaitOnAjaxRequest();
     $assert_session->pageTextContains('Media library');
-
     // Assert the default tab for media type one does not have an upload form.
     $assert_session->fieldNotExists('files[upload][]');
-
     // Assert we can upload a file to media type three.
     $page->clickLink('Type Three');
     $assert_session->assertWaitOnAjaxRequest();
@@ -606,17 +604,15 @@
     $assert_session->assertWaitOnAjaxRequest();
     $assert_session->elementExists('css', '.media-library-add-form--with-input');
     $assert_session->elementNotExists('css', '.media-library-add-form--without-input');
-
+    $assert_session->elementNotExists('css', '.media-library-add-form-selection');
     // Files are temporary until the form is saved.
     $files = $file_storage->loadMultiple();
     $file = array_pop($files);
     $this->assertSame('public://type-three-dir', $file_system->dirname($file->getFileUri()));
     $this->assertTrue($file->isTemporary());
-
     // Assert the revision_log_message field is not shown.
     $upload_form = $assert_session->elementExists('css', '.media-library-add-form');
     $assert_session->fieldNotExists('Revision log message', $upload_form);
-
     // Assert the name field contains the filename and the alt text is required.
     $this->assertSame($assert_session->fieldExists('Name')->getValue(), $png_image->filename);
     $assert_session->elementExists('css', '.ui-dialog-buttonpane')->pressButton('Save and select');
@@ -625,17 +621,14 @@
     $page->fillField('Alternative text', $this->randomString());
     $assert_session->elementExists('css', '.ui-dialog-buttonpane')->pressButton('Save and select');
     $assert_session->assertWaitOnAjaxRequest();
-
     // The file should be permanent now.
     $files = $file_storage->loadMultiple();
     $file = array_pop($files);
     $this->assertFalse($file->isTemporary());
-
     // Load the created media item.
     $media_storage = $this->container->get('entity_type.manager')->getStorage('media');
     $media_items = $media_storage->loadMultiple();
     $added_media = array_pop($media_items);
-
     // Ensure the media item was saved to the library and automatically
     // selected. The added media items should be in the first position of the
     // add form.
@@ -644,7 +637,7 @@
     $assert_session->fieldValueEquals('media_library_select_form[0]', $added_media->id());
     $assert_session->checkboxChecked('media_library_select_form[0]');
     $assert_session->pageTextContains('1 of 2 items selected');
-
+    $assert_session->hiddenFieldValueEquals('current_selection', $added_media->id());
     // Ensure the created item is added in the widget.
     $assert_session->elementExists('css', '.ui-dialog-buttonpane')->pressButton('Insert selected');
     $assert_session->assertWaitOnAjaxRequest();
@@ -662,43 +655,46 @@
     $assert_session->pageTextContains('Media library');
     $page->clickLink('Type Three');
     $assert_session->assertWaitOnAjaxRequest();
-    $page->attachFileToField('Add files', $this->container->get('file_system')->realpath($png_image->uri));
+    $png_uri_2 = file_unmanaged_copy($png_image->uri);
+    $page->attachFileToField('Add files', $this->container->get('file_system')->realpath($png_uri_2));
     $assert_session->assertWaitOnAjaxRequest();
     $page->fillField('Alternative text', $this->randomString());
     $assert_session->elementExists('css', '.ui-dialog-buttonpane')->pressButton('Save and insert');
     $assert_session->assertWaitOnAjaxRequest();
     $assert_session->pageTextNotContains('Media library');
-    $assert_session->pageTextContains($png_image->filename);
+    $assert_session->pageTextContains($file_system->basename($png_uri_2));
 
     // Also make sure that we can upload to the unlimited cardinality field.
     $assert_session->elementExists('css', '.media-library-open-button[href*="field_unlimited_media"]')->click();
     $assert_session->assertWaitOnAjaxRequest();
     $assert_session->pageTextContains('Media library');
-
-    // Navigate to the media type three tab first.
     $page->clickLink('Type Three');
     $assert_session->assertWaitOnAjaxRequest();
-
-    // Select a media item.
-    $page->find('css', '.media-library-view .js-click-to-select-checkbox input')->click();
+    // Select a media item to check if the selection is persisted when adding
+    // new items.
+    $existing_media_name = $file_system->basename($png_uri_2);
+    $checkbox = $page->findField("Select $existing_media_name");
+    $selected_item_id = $checkbox->getAttribute('value');
+    $checkbox->click();
     $assert_session->pageTextContains('1 item selected');
-
+    $assert_session->hiddenFieldValueEquals('current_selection', $selected_item_id);
     // Multiple uploads should be allowed.
     // @todo Add test when https://github.com/minkphp/Mink/issues/358 is closed
     $this->assertTrue($assert_session->fieldExists('Add files')->hasAttribute('multiple'));
-
-    $page->attachFileToField('Add files', $this->container->get('file_system')->realpath($png_image->uri));
+    $png_uri_3 = file_unmanaged_copy($png_image->uri);
+    $page->attachFileToField('Add files', $this->container->get('file_system')->realpath($png_uri_3));
     $assert_session->assertWaitOnAjaxRequest();
+    $selection_area = $assert_session->elementExists('css', '.media-library-add-form-selection');
+    $assert_session->checkboxChecked("Select $existing_media_name", $selection_area);
     $page->fillField('Name', 'Unlimited Cardinality Image');
     $page->fillField('Alternative text', $this->randomString());
     $assert_session->elementExists('css', '.ui-dialog-buttonpane')->pressButton('Save and select');
     $assert_session->assertWaitOnAjaxRequest();
-
     // Load the created media item.
     $media_storage = $this->container->get('entity_type.manager')->getStorage('media');
     $media_items = $media_storage->loadMultiple();
     $added_media = array_pop($media_items);
-
+    $added_media_name = $added_media->label();
     // Ensure the media item was saved to the library and automatically
     // selected. The added media items should be in the first position of the
     // add form.
@@ -706,69 +702,101 @@
     $assert_session->pageTextContains('Unlimited Cardinality Image');
     $assert_session->fieldValueEquals('media_library_select_form[0]', $added_media->id());
     $assert_session->checkboxChecked('media_library_select_form[0]');
-
     // Assert the item that was selected before uploading the file is still
     // selected.
     $assert_session->pageTextContains('2 items selected');
+    $assert_session->checkboxChecked("Select $added_media_name");
+    $assert_session->checkboxChecked("Select $existing_media_name");
+    $assert_session->hiddenFieldValueEquals('current_selection', implode(',', [$selected_item_id, $added_media->id()]));
     $checkboxes = $page->findAll('css', '.media-library-view .js-click-to-select-checkbox input');
     $selected_checkboxes = [];
     foreach ($checkboxes as $checkbox) {
       if ($checkbox->isChecked()) {
-        $selected_checkboxes[] = $checkbox->getValue();
+        $selected_checkboxes[] = $checkbox->getAttribute('value');
       }
     }
     $this->assertCount(2, $selected_checkboxes);
-
     // Ensure the created item is added in the widget.
     $assert_session->elementExists('css', '.ui-dialog-buttonpane')->pressButton('Insert selected');
     $assert_session->assertWaitOnAjaxRequest();
     $assert_session->pageTextNotContains('Media library');
     $assert_session->pageTextContains('Unlimited Cardinality Image');
 
-    // Verify we can only upload the files allowed by the media type.
+    // Assert we can now only upload one more media item.
     $assert_session->elementExists('css', '.media-library-open-button[href*="field_twin_media"]')->click();
     $assert_session->assertWaitOnAjaxRequest();
     $assert_session->pageTextContains('Media library');
     $page->clickLink('Type Four');
     $assert_session->assertWaitOnAjaxRequest();
-
-    // Assert we can now only upload one more media item.
     $this->assertFalse($assert_session->fieldExists('Add file')->hasAttribute('multiple'));
     $assert_session->pageTextContains('One file only.');
 
     // Assert media type four should only allow jpg files by trying a png file
     // first.
-    $page->attachFileToField('Add file', $file_system->realpath($png_image->uri));
+    $png_uri_4 = file_unmanaged_copy($png_image->uri);
+    $page->attachFileToField('Add file', $file_system->realpath($png_uri_4));
     $assert_session->assertWaitOnAjaxRequest();
     $assert_session->pageTextContains('Only files with the following extensions are allowed');
-
     // Assert that jpg files are accepted by type four.
-    $page->attachFileToField('Add file', $file_system->realpath($jpg_image->uri));
+    $jpg_uri_2 = file_unmanaged_copy($jpg_image->uri);
+    $page->attachFileToField('Add file', $file_system->realpath($jpg_uri_2));
     $assert_session->assertWaitOnAjaxRequest();
     $page->fillField('Alternative text', $this->randomString());
-
     // The type_four media type has another optional image field.
     $assert_session->pageTextContains('Extra Image');
-    $page->attachFileToField('Extra Image', $this->container->get('file_system')->realpath($jpg_image->uri));
+    $jpg_uri_3 = file_unmanaged_copy($jpg_image->uri);
+    $page->attachFileToField('Extra Image', $this->container->get('file_system')->realpath($jpg_uri_3));
     $assert_session->assertWaitOnAjaxRequest();
     // Ensure that the extra image was uploaded to the correct directory.
     $files = $file_storage->loadMultiple();
     $file = array_pop($files);
     $this->assertSame('public://type-four-extra-dir', $file_system->dirname($file->getFileUri()));
-
     $assert_session->elementExists('css', '.ui-dialog-buttonpane')->pressButton('Save and select');
     $assert_session->assertWaitOnAjaxRequest();
-
     // Ensure the media item was saved to the library and automatically
     // selected.
     $assert_session->pageTextContains('Media library');
-    $assert_session->pageTextContains($jpg_image->filename);
-
+    $assert_session->pageTextContains($file_system->basename($jpg_uri_2));
     // Ensure the created item is added in the widget.
     $assert_session->elementExists('css', '.ui-dialog-buttonpane')->pressButton('Insert selected');
     $assert_session->assertWaitOnAjaxRequest();
     $assert_session->pageTextNotContains('Media library');
-    $assert_session->pageTextContains($jpg_image->filename);
+    $assert_session->pageTextContains($file_system->basename($jpg_uri_2));
+
+    // Assert we can also remove selected items from the selection area in the
+    // upload form.
+    $assert_session->elementExists('css', '.media-library-open-button[href*="field_unlimited_media"]')->click();
+    $assert_session->assertWaitOnAjaxRequest();
+    $assert_session->pageTextContains('Media library');
+    $page->clickLink('Type Three');
+    $assert_session->assertWaitOnAjaxRequest();
+    $checkbox = $page->findField("Select $existing_media_name");
+    $selected_item_id = $checkbox->getAttribute('value');
+    $checkbox->click();
+    $assert_session->hiddenFieldValueEquals('current_selection', $selected_item_id);
+    $this->assertTrue($assert_session->fieldExists('Add files')->hasAttribute('multiple'));
+    $png_uri_5 = file_unmanaged_copy($png_image->uri);
+    $page->attachFileToField('Add files', $this->container->get('file_system')->realpath($png_uri_5));
+    $assert_session->assertWaitOnAjaxRequest();
+    $selection_area = $assert_session->elementExists('css', '.media-library-add-form-selection');
+    $assert_session->checkboxChecked("Select $existing_media_name", $selection_area);
+    $page->uncheckField("Select $existing_media_name");
+    $page->fillField('Alternative text', $this->randomString());
+    $assert_session->hiddenFieldValueEquals('current_selection', '');
+    $assert_session->elementExists('css', '.ui-dialog-buttonpane')->pressButton('Save and select');
+    $assert_session->assertWaitOnAjaxRequest();
+    $media_storage = $this->container->get('entity_type.manager')->getStorage('media');
+    $media_items = $media_storage->loadMultiple();
+    $added_media = array_pop($media_items);
+    $added_media_name = $added_media->label();
+    $assert_session->pageTextContains('1 item selected');
+    $assert_session->checkboxChecked("Select $added_media_name");
+    $assert_session->checkboxNotChecked("Select $existing_media_name");
+    $assert_session->hiddenFieldValueEquals('current_selection', $added_media->id());
+    $assert_session->elementExists('css', '.ui-dialog-buttonpane')->pressButton('Insert selected');
+    $assert_session->assertWaitOnAjaxRequest();
+    $assert_session->pageTextNotContains('Media library');
+    $assert_session->pageTextContains($file_system->basename($png_uri_5));
   }
 
 }
only in patch2:
unchanged:
--- a/core/modules/media_library/css/media_library.module.css
+++ b/core/modules/media_library/css/media_library.module.css
@@ -24,6 +24,7 @@
 
 .media-library-views-form,
 .media-library-selection,
+.media-library-add-form-selection,
 .media-library-views-form__bulk_form,
 .media-library-view .form--inline {
   display: flex;
@@ -81,7 +82,8 @@
 
 /* @todo Remove or re-work in https://www.drupal.org/node/2985168 */
 .media-library-widget .media-library-item__name a,
-.media-library-view.view-display-id-widget .media-library-item__name a {
+.media-library-view.view-display-id-widget .media-library-item__name a,
+.media-library-add-form-selection .media-library-item__name a {
   pointer-events: none;
 }
 
only in patch2:
unchanged:
--- a/core/modules/media_library/css/media_library.theme.css
+++ b/core/modules/media_library/css/media_library.theme.css
@@ -96,6 +96,11 @@
   margin: 8px 0 0;
 }
 
+.media-library-add-form-selection {
+  margin-top: 1em;
+  border-top: 1px solid #c0c0c0;
+}
+
 .media-library-views-form__header .form-item {
   margin-right: 8px;
 }
@@ -303,8 +308,8 @@
 
 /* Do not show the bottom border and padding for the last item. */
 .media-library-add-form__media:last-child {
-  border-bottom: 0;
   padding-bottom: 0;
+  border-bottom: 0;
 }
 
 /* @todo Remove in https://www.drupal.org/project/drupal/issues/2987921 */
@@ -331,7 +336,8 @@
 
 /* @todo Remove or re-work in https://www.drupal.org/node/2985168 */
 .media-library-widget .media-library-item__name a,
-.media-library-view.view-display-id-widget .media-library-item__name a {
+.media-library-view.view-display-id-widget .media-library-item__name a,
+.media-library-add-form-selection .media-library-item__name a {
   text-decoration: none;
   color: black;
 }
only in patch2:
unchanged:
--- a/core/modules/media_library/js/media_library.click_to_select.es6.js
+++ b/core/modules/media_library/js/media_library.click_to_select.es6.js
@@ -33,4 +33,44 @@
         });
     },
   };
+
+  /**
+   * Adds hover effect to media items.
+   *
+   * @type {Drupal~behavior}
+   *
+   * @prop {Drupal~behaviorAttach} attach
+   *   Attaches behavior to add a class when hovering over media items.
+   */
+  Drupal.behaviors.ClickToSelectHover = {
+    attach(context) {
+      $('.js-click-to-select-trigger, .js-click-to-select-checkbox', context)
+        .once('media-library-item-hover')
+        .on('mouseover mouseout', ({ currentTarget, type }) => {
+          $(currentTarget)
+            .closest('.media-library-item')
+            .toggleClass('is-hover', type === 'mouseover');
+        });
+    },
+  };
+
+  /**
+   * Adds focus effect to media items.
+   *
+   * @type {Drupal~behavior}
+   *
+   * @prop {Drupal~behaviorAttach} attach
+   *   Attaches behavior to add a focus effect to media items.
+   */
+  Drupal.behaviors.ClickToSelectFocus = {
+    attach(context) {
+      $('.js-click-to-select-checkbox input', context)
+        .once('media-library-item-focus')
+        .on('focus blur', ({ currentTarget, type }) => {
+          $(currentTarget)
+            .closest('.media-library-item')
+            .toggleClass('is-focus', type === 'focus');
+        });
+    },
+  };
 })(jQuery, Drupal);
only in patch2:
unchanged:
--- a/core/modules/media_library/js/media_library.click_to_select.js
+++ b/core/modules/media_library/js/media_library.click_to_select.js
@@ -21,4 +21,26 @@
       });
     }
   };
+
+  Drupal.behaviors.ClickToSelectHover = {
+    attach: function attach(context) {
+      $('.js-click-to-select-trigger, .js-click-to-select-checkbox', context).once('media-library-item-hover').on('mouseover mouseout', function (_ref2) {
+        var currentTarget = _ref2.currentTarget,
+            type = _ref2.type;
+
+        $(currentTarget).closest('.media-library-item').toggleClass('is-hover', type === 'mouseover');
+      });
+    }
+  };
+
+  Drupal.behaviors.ClickToSelectFocus = {
+    attach: function attach(context) {
+      $('.js-click-to-select-checkbox input', context).once('media-library-item-focus').on('focus blur', function (_ref3) {
+        var currentTarget = _ref3.currentTarget,
+            type = _ref3.type;
+
+        $(currentTarget).closest('.media-library-item').toggleClass('is-focus', type === 'focus');
+      });
+    }
+  };
 })(jQuery, Drupal);
\ No newline at end of file
only in patch2:
unchanged:
--- a/core/modules/media_library/js/media_library.ui.es6.js
+++ b/core/modules/media_library/js/media_library.ui.es6.js
@@ -150,7 +150,10 @@
    */
   Drupal.behaviors.MediaLibraryItemSelection = {
     attach(context, settings) {
-      const $form = $('.js-media-library-views-form', context);
+      const $form = $(
+        '.js-media-library-views-form, .js-media-library-add-form',
+        context,
+      );
       const currentSelection = Drupal.MediaLibrary.currentSelection;
 
       if (!$form.length) {
@@ -162,30 +165,6 @@
         $form,
       );
 
-      // Update the selection array and the hidden form field when a media item
-      // is selected.
-      $mediaItems.once('media-item-change').on('change', e => {
-        const id = e.currentTarget.value;
-
-        // Update the selection.
-        const position = currentSelection.indexOf(id);
-        if (e.currentTarget.checked) {
-          // Check if the ID is not already in the selection and add if needed.
-          if (position === -1) {
-            currentSelection.push(id);
-          }
-        } else if (position !== -1) {
-          // Remove the ID when it is in the current selection.
-          currentSelection.splice(position, 1);
-        }
-
-        // Set the selection in the hidden form element.
-        $form
-          .find('#media-library-modal-selection')
-          .val(currentSelection.join())
-          .trigger('change');
-      });
-
       /**
        * Disable media items.
        *
@@ -242,23 +221,49 @@
         }
       }
 
-      // The hidden selection form field changes when the selection is updated.
-      $('#media-library-modal-selection', $form)
-        .once('media-library-selection-change')
-        .on('change', e => {
-          updateSelectionInfo(settings.media_library.selection_remaining);
+      // Update the selection array and the hidden form field when a media item
+      // is selected.
+      $mediaItems.once('media-item-change').on('change', e => {
+        const id = e.currentTarget.value;
 
-          // Prevent users from selecting more items than allowed.
-          if (
-            currentSelection.length ===
-            settings.media_library.selection_remaining
-          ) {
-            disableItems($mediaItems.not(':checked'));
-            enableItems($mediaItems.filter(':checked'));
-          } else {
-            enableItems($mediaItems);
+        // Update the selection.
+        const position = currentSelection.indexOf(id);
+        if (e.currentTarget.checked) {
+          // Check if the ID is not already in the selection and add if needed.
+          if (position === -1) {
+            currentSelection.push(id);
           }
-        });
+        } else if (position !== -1) {
+          // Remove the ID when it is in the current selection.
+          currentSelection.splice(position, 1);
+        }
+
+        // Set the selection in the hidden form element.
+        $form
+          .find('#media-library-modal-selection')
+          .val(currentSelection.join())
+          .trigger('change');
+
+        // Set the selection in the media library add form. Since the form is
+        // not necessarily loaded within the same context, we can't use the
+        // context here.
+        $('.js-media-library-add-form-current-selection').val(
+          currentSelection.join(),
+        );
+
+        // Update the number of selected items in the button pane.
+        updateSelectionInfo(settings.media_library.selection_remaining);
+
+        // Prevent users from selecting more items than allowed.
+        if (
+          currentSelection.length === settings.media_library.selection_remaining
+        ) {
+          disableItems($mediaItems.not(':checked'));
+          enableItems($mediaItems.filter(':checked'));
+        } else {
+          enableItems($mediaItems);
+        }
+      });
 
       // Apply the current selection to the media library view. Changing the
       // checkbox values triggers the change event for the media items. The
only in patch2:
unchanged:
--- a/core/modules/media_library/js/media_library.ui.js
+++ b/core/modules/media_library/js/media_library.ui.js
@@ -77,7 +77,7 @@
 
   Drupal.behaviors.MediaLibraryItemSelection = {
     attach: function attach(context, settings) {
-      var $form = $('.js-media-library-views-form', context);
+      var $form = $('.js-media-library-views-form, .js-media-library-add-form', context);
       var currentSelection = Drupal.MediaLibrary.currentSelection;
 
       if (!$form.length) {
@@ -86,21 +86,6 @@
 
       var $mediaItems = $('.js-media-library-item input[type="checkbox"]', $form);
 
-      $mediaItems.once('media-item-change').on('change', function (e) {
-        var id = e.currentTarget.value;
-
-        var position = currentSelection.indexOf(id);
-        if (e.currentTarget.checked) {
-          if (position === -1) {
-            currentSelection.push(id);
-          }
-        } else if (position !== -1) {
-          currentSelection.splice(position, 1);
-        }
-
-        $form.find('#media-library-modal-selection').val(currentSelection.join()).trigger('change');
-      });
-
       function disableItems($items) {
         $items.prop('disabled', true).closest('.js-media-library-item').addClass('media-library-item--disabled');
       }
@@ -124,7 +109,22 @@
         }
       }
 
-      $('#media-library-modal-selection', $form).once('media-library-selection-change').on('change', function (e) {
+      $mediaItems.once('media-item-change').on('change', function (e) {
+        var id = e.currentTarget.value;
+
+        var position = currentSelection.indexOf(id);
+        if (e.currentTarget.checked) {
+          if (position === -1) {
+            currentSelection.push(id);
+          }
+        } else if (position !== -1) {
+          currentSelection.splice(position, 1);
+        }
+
+        $form.find('#media-library-modal-selection').val(currentSelection.join()).trigger('change');
+
+        $('.js-media-library-add-form-current-selection').val(currentSelection.join());
+
         updateSelectionInfo(settings.media_library.selection_remaining);
 
         if (currentSelection.length === settings.media_library.selection_remaining) {
only in patch2:
unchanged:
--- a/core/modules/media_library/js/media_library.view.es6.js
+++ b/core/modules/media_library/js/media_library.view.es6.js
@@ -2,46 +2,6 @@
  * @file media_library.view.es6.js
  */
 (($, Drupal) => {
-  /**
-   * Adds hover effect to media items.
-   *
-   * @type {Drupal~behavior}
-   *
-   * @prop {Drupal~behaviorAttach} attach
-   *   Attaches behavior to add a class when hovering over media items.
-   */
-  Drupal.behaviors.MediaLibraryHover = {
-    attach(context) {
-      $('.js-click-to-select-trigger, .js-click-to-select-checkbox', context)
-        .once('media-library-item-hover')
-        .on('mouseover mouseout', ({ currentTarget, type }) => {
-          $(currentTarget)
-            .closest('.media-library-item')
-            .toggleClass('is-hover', type === 'mouseover');
-        });
-    },
-  };
-
-  /**
-   * Adds focus effect to media items.
-   *
-   * @type {Drupal~behavior}
-   *
-   * @prop {Drupal~behaviorAttach} attach
-   *   Attaches behavior to add a focus effect to media items.
-   */
-  Drupal.behaviors.MediaLibraryFocus = {
-    attach(context) {
-      $('.js-click-to-select-checkbox input', context)
-        .once('media-library-item-focus')
-        .on('focus blur', ({ currentTarget, type }) => {
-          $(currentTarget)
-            .closest('.media-library-item')
-            .toggleClass('is-focus', type === 'focus');
-        });
-    },
-  };
-
   /**
    * Adds checkbox to select all items in the library.
    *
only in patch2:
unchanged:
--- a/core/modules/media_library/js/media_library.view.js
+++ b/core/modules/media_library/js/media_library.view.js
@@ -6,34 +6,12 @@
 **/
 
 (function ($, Drupal) {
-  Drupal.behaviors.MediaLibraryHover = {
-    attach: function attach(context) {
-      $('.js-click-to-select-trigger, .js-click-to-select-checkbox', context).once('media-library-item-hover').on('mouseover mouseout', function (_ref) {
-        var currentTarget = _ref.currentTarget,
-            type = _ref.type;
-
-        $(currentTarget).closest('.media-library-item').toggleClass('is-hover', type === 'mouseover');
-      });
-    }
-  };
-
-  Drupal.behaviors.MediaLibraryFocus = {
-    attach: function attach(context) {
-      $('.js-click-to-select-checkbox input', context).once('media-library-item-focus').on('focus blur', function (_ref2) {
-        var currentTarget = _ref2.currentTarget,
-            type = _ref2.type;
-
-        $(currentTarget).closest('.media-library-item').toggleClass('is-focus', type === 'focus');
-      });
-    }
-  };
-
   Drupal.behaviors.MediaLibrarySelectAll = {
     attach: function attach(context) {
       var $view = $('.js-media-library-view', context).once('media-library-select-all');
       if ($view.length && $view.find('.media-library-item').length) {
-        var $checkbox = $('<input type="checkbox" class="form-checkbox" />').on('click', function (_ref3) {
-          var currentTarget = _ref3.currentTarget;
+        var $checkbox = $('<input type="checkbox" class="form-checkbox" />').on('click', function (_ref) {
+          var currentTarget = _ref.currentTarget;
 
           var $checkboxes = $(currentTarget).closest('.media-library-view').find('.media-library-item input[type="checkbox"]');
           $checkboxes.prop('checked', $(currentTarget).prop('checked')).trigger('change');
only in patch2:
unchanged:
--- a/core/modules/media_library/src/Form/FileUploadForm.php
+++ b/core/modules/media_library/src/Form/FileUploadForm.php
@@ -176,6 +176,7 @@ public function validateUploadElement(array $element, FormStateInterface $form_s
    */
   public function processUploadElement(array $element, FormStateInterface $form_state) {
     $element['upload_button']['#submit'] = ['::uploadButtonSubmit'];
+    $element['upload_button']['#limit_validation_errors'] = FALSE;
     $element['upload_button']['#ajax'] = [
       'callback' => '::updateFormCallback',
       'wrapper' => 'media-library-wrapper',