Issue #2596649 by legolasbo, rakesh.gectcr: Exposed form does not save state...

Issue #2596649 by legolasbo, rakesh.gectcr: Exposed form does not save state when it is placed in a block

core/modules/views/src/Plugin/Block/ViewsExposedFilterBlock.php

@@ -6,6 +6,7 @@
  */
 
 namespace Drupal\views\Plugin\Block;
+use Drupal\Core\Cache\Cache;
 
 /**
  * Provides a 'Views Exposed Filter' block.
@@ -18,11 +19,20 @@
  */
 class ViewsExposedFilterBlock extends ViewsBlockBase {
 
+  /**
+   * {@inheritdoc}
+   */
+  public function getCacheContexts() {
+    $contexts = $this->view->display_handler->getCacheMetadata()->getCacheContexts();
+    return Cache::mergeContexts(parent::getCacheContexts(), $contexts);
+  }
+
   /**
    * {@inheritdoc}
    */
   public function build() {
     $output = $this->view->display_handler->viewExposedFormBlocks();
+
     // Before returning the block output, convert it to a renderable array with
     // contextual links.
     $this->addContextualLinks($output, 'exposed_filter');

core/modules/views/src/Plugin/views/exposed_form/ExposedFormPluginBase.php

@@ -359,6 +359,14 @@ public function getCacheContexts() {
       }
     }
 
+    // Merge in cache contexts for all exposed filters to prevent display of
+    // cached forms.
+    foreach ($this->displayHandler->getHandlers('filter') as $filter_hander) {
+      if ($filter_hander->isExposed()) {
+        $contexts = Cache::mergeContexts($contexts, $filter_hander->getCacheContexts());
+      }
+    }
+
     return $contexts;
   }
 

core/modules/views/src/Tests/Plugin/ExposedFormTest.php

@@ -151,6 +151,7 @@ public function testExposedFormRender() {
    * Tests the exposed block functionality.
    */
   public function testExposedBlock() {
+    $this->drupalCreateContentType(['type' => 'page']);
     $view = Views::getView('test_exposed_block');
     $view->setDisplay('page_1');
     $block = $this->drupalPlaceBlock('views_exposed_filter_block:test_exposed_block-page_1');
@@ -167,6 +168,15 @@ public function testExposedBlock() {
     // Test there is only one views exposed form on the page.
     $elements = $this->xpath('//form[@id=:id]', array(':id' => $this->getExpectedExposedFormId($view)));
     $this->assertEqual(count($elements), 1, 'One exposed form block found.');
+
+    // Test that the correct option is selected after form submission.
+    $this->assertCacheContext('url');
+    $this->assertOptionSelected('edit-type','All');
+    foreach (['All', 'article', 'page'] as $argument) {
+      $this->drupalGet('test_exposed_block', ['query' => ['type' => $argument]]);
+      $this->assertCacheContext('url');
+      $this->assertOptionSelected('edit-type', $argument);
+    }
   }
 
   /**