only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/views/src/Tests/ViewsFormMultipleTest.php
@@ -0,0 +1,47 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\views\Tests\ViewsFormMultipleTest.
+ */
+
+namespace Drupal\views\Tests;
+
+/**
+ * Tests a page with multiple Views forms.
+ *
+ * @group views
+ */
+class ViewsFormMultipleTest extends ViewTestBase {
+
+  /**
+   * Views used by this test.
+   *
+   * @var array
+   */
+  public static $testViews = ['test_form_multiple'];
+
+  protected function setUp() {
+    parent::setUp();
+
+    $this->enableViewsTestModule();
+  }
+
+  /**
+   * Tests the a page with multiple View forms in it.
+   */
+  public function testViewsFormMultiple() {
+    // Get the test page.
+    $this->drupalGet('views_test_form_multiple');
+
+    // Look for the first button of the second view form.
+    // @todo.
+
+    // Submit the form for the button found.
+    // @todo.
+
+    // Display the message returned by the button submission.
+    // @todo.
+  }
+
+}
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/views/tests/modules/views_test_config/test_views/views.view.test_form_multiple.yml
@@ -0,0 +1,130 @@
+langcode: en
+status: true
+dependencies:
+  module:
+    - node
+id: test_form_multiple
+label: ''
+module: views
+description: ''
+tag: ''
+base_table: views_test_data
+base_field: nid
+core: 8.x
+display:
+  default:
+    display_plugin: default
+    display_title: Master
+    id: default
+    position: 0
+    display_options:
+      access:
+        type: none
+      cache:
+        type: tag
+        options: {  }
+      query:
+        type: views_query
+        options:
+          disable_sql_rewrite: false
+          distinct: false
+          replica: false
+          query_comment: ''
+          query_tags: {  }
+      pager:
+        options:
+          id: 0
+          items_per_page: 10
+          offset: 0
+        type: full
+      style:
+        type: table
+        options:
+          grouping: {  }
+          row_class: ''
+          default_row_class: true
+          override: true
+          sticky: false
+          caption: ''
+          summary: ''
+          description: ''
+          columns:
+            id: id
+            field_form_button_test: field_form_button_test
+          info:
+            field_form_button_test:
+              sortable: false
+              default_sort_order: asc
+              align: ''
+              separator: ''
+              empty_column: false
+              responsive: ''
+          default: '-1'
+          empty_table: false
+      row:
+        type: fields
+      fields:
+        id:
+          field: id
+          id: id
+          relationship: none
+          table: views_test_data
+          plugin_id: numeric
+        field_form_button_test:
+          id: field_form_button_test
+          table: views
+          field: field_form_button_test
+          relationship: none
+          group_type: group
+          admin_label: ''
+          label: 'Field form button test'
+          exclude: false
+          alter:
+            alter_text: false
+            text: ''
+            make_link: false
+            path: ''
+            absolute: false
+            external: false
+            replace_spaces: false
+            path_case: none
+            trim_whitespace: false
+            alt: ''
+            rel: ''
+            link_class: ''
+            prefix: ''
+            suffix: ''
+            target: ''
+            nl2br: false
+            max_length: 0
+            word_boundary: true
+            ellipsis: true
+            more_link: false
+            more_link_text: ''
+            more_link_path: ''
+            strip_tags: false
+            trim: false
+            preserve_tags: ''
+            html: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: true
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_empty: false
+          empty_zero: false
+          hide_alter_empty: true
+          plugin_id: field_form_button_test
+      arguments:
+        'null':
+          default_action: default
+          default_argument_type: fixed
+          field: 'null'
+          id: 'null'
+          must_not_be: false
+          table: views
+          plugin_id: 'null'
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/views/tests/modules/views_test_data/src/Controller/ViewsTestFormMultipleController.php
@@ -0,0 +1,44 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\views_test_data\Controller\ViewsTestFormMultipleController.
+ */
+
+namespace Drupal\views_test_data\Controller;
+
+use Drupal\Core\Controller\ControllerBase;
+
+/**
+ * Controller routines for views form multiple test routes.
+ */
+class ViewsTestFormMultipleController extends ControllerBase {
+
+  /**
+   * Returns a test page having test_form_multiple view embeded twice.
+   */
+  public function testPage() {
+    $build = [
+      'view_arg1' => [
+        '#prefix' => '<div class="view-test-form-multiple-1">',
+        '#suffix' => '</div>',
+        '#type' => 'view',
+        '#name' => 'test_form_multiple',
+        '#display_id' => 'default',
+        '#arguments' => ['arg1'],
+        '#embed' => TRUE,
+      ],
+      'view_arg2' => [
+        '#prefix' => '<div class="view-test-form-multiple-2">',
+        '#suffix' => '</div>',
+        '#type' => 'view',
+        '#name' => 'test_form_multiple',
+        '#display_id' => 'default',
+        '#arguments' => ['arg2'],
+        '#embed' => TRUE,
+      ],
+    ];
+    return $build;
+  }
+
+}
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/views/tests/modules/views_test_data/src/Plugin/views/field/FieldFormButtonTest.php
@@ -0,0 +1,87 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\views_test_data\Plugin\views\field\FieldFormButtonTest.
+ */
+
+namespace Drupal\views_test_data\Plugin\views\field;
+
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\views\Plugin\views\field\FieldPluginBase;
+use Drupal\views\Plugin\views\field\UncacheableFieldHandlerTrait;
+use Drupal\views\ResultRow;
+
+/**
+ * A handler to provide a field that is completely custom by the administrator.
+ *
+ * @ingroup views_field_handlers
+ *
+ * @ViewsField("field_form_button_test")
+ */
+class FieldFormButtonTest extends FieldPluginBase {
+
+  use UncacheableFieldHandlerTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getValue(ResultRow $row, $field = NULL) {
+    return '<!--form-item-' . $this->options['id'] . '--' . $row->index . '-->';
+  }
+
+  /**
+   * Form constructor for the views form.
+   *
+   * @param array $form
+   *   An associative array containing the structure of the form.
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   The current state of the form.
+   */
+  public function viewsForm(&$form, FormStateInterface $form_state) {
+    // Make sure we do not accidentally cache this form.
+    $form['#cache']['max-age'] = 0;
+    // The view is empty, abort.
+    if (empty($this->view->result)) {
+      unset($form['actions']);
+      return;
+    }
+
+    $form[$this->options['id']]['#tree'] = TRUE;
+    foreach ($this->view->result as $row_index => $row) {
+      $form[$this->options['id']][$row_index] = [
+        '#type' => 'submit',
+        '#value' => t('Test Button'),
+        '#name' => 'test-button-' . $row_index,
+        '#test_button' => TRUE,
+        '#row_index' => $row_index,
+        '#attributes' => ['class' => ['test-button']],
+      ];
+    }
+  }
+
+  /**
+   * Submit handler for the views form.
+   *
+   * @param array $form
+   *   An associative array containing the structure of the form.
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   The current state of the form.
+   */
+  public function viewsFormSubmit(&$form, FormStateInterface $form_state) {
+    $triggering_element = $form_state->getTriggeringElement();
+    if (!empty($triggering_element['#test_button'])) {
+      $row_index = $triggering_element['#row_index'];
+      $view_args = !empty($this->view->args) ? implode(', ', $this->view->args) : $this->t('no arguments');
+      drupal_set_message($this->t('The test button for @view_title (@display / @view_id) View with args: @args was submitted.', array('@view_title' => $this->view->getTitle(), '@display' => $this->view->current_display, '@view_id' => $this->view->id(), '@args' => $view_args)));
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function query() {
+    // Do nothing.
+  }
+
+}
only in patch2:
unchanged:
--- a/core/modules/views/tests/modules/views_test_data/views_test_data.routing.yml
+++ b/core/modules/views/tests/modules/views_test_data/views_test_data.routing.yml
@@ -11,3 +11,11 @@ views_test_data.element_embed:
     _form: '\Drupal\views_test_data\Form\ViewsTestDataElementEmbedForm'
   requirements:
     _access: 'TRUE'
+
+views_test_data.form_multiple:
+  path: '/views_test_form_multiple'
+  defaults:
+    _title: 'Test Views Form Multiple'
+    _controller: '\Drupal\views_test_data\Controller\ViewsTestFormMultipleController::testPage'
+  requirements:
+    _access: 'TRUE'