Issue #3132426 by alexpott, dww, GuyPaddock, catch, VladimirAus: Notice: Undefined index: title in Drupal\update\ProjectSecurityRequirement

core/modules/update/src/UpdateManagerInterface.php

@@ -82,8 +82,14 @@ interface UpdateManagerInterface {
   /**
    * Processes a step in batch for fetching available update data.
    *
+   * Before calling this method, call
+   * UpdateManagerInterface::refreshUpdateData() to clear existing update data
+   * and initiate re-fetching.
+   *
    * @param array $context
    *   Reference to an array used for Batch API storage.
+   *
+   * @see \Drupal\update\UpdateManagerInterface::refreshUpdateData()
    */
   public function fetchDataBatch(&$context);
 

core/modules/update/src/UpdateProcessor.php

@@ -127,6 +127,11 @@ class UpdateProcessor implements UpdateProcessorInterface {
    */
   public function fetchData() {
     $end = time() + $this->updateSettings->get('fetch.timeout');
+    if ($this->fetchQueue->numberOfItems()) {
+      // Delete any stored project data as that needs refreshing when
+      // update_calculate_project_data() is called.
+      $this->tempStore->delete('update_project_data');
+    }
     while (time() < $end && ($item = $this->fetchQueue->claimItem())) {
       $this->processFetchTask($item->data);
       $this->fetchQueue->deleteItem($item);

core/modules/update/tests/fixtures/release-history/drupal.broken.xml

@@ -0,0 +1,3 @@
+<?xml version="1.0" encoding="utf-8"?>
+<project xmlns:dc="http://purl.org/dc/elements/1.1/">
+</project>

core/modules/update/tests/src/Functional/UpdateCoreTest.php

@@ -862,6 +862,43 @@ class UpdateCoreTest extends UpdateTestBase {
     }
   }
 
+  /**
+   * Checks that Drupal recovers after problems connecting to update server.
+   */
+  public function testBrokenThenFixedUpdates() {
+    $this->drupalLogin($this->drupalCreateUser([
+      'administer site configuration',
+      'access administration pages',
+    ]));
+    $this->setSystemInfo('8.0.0');
+    // Instead of using refreshUpdateStatus(), set these manually.
+    $this->config('update.settings')
+      ->set('fetch.url', Url::fromRoute('update_test.update_test')->setAbsolute()->toString())
+      ->save();
+    // Use update XML that has no information to simulate a broken response from
+    // the update server.
+    $this->config('update_test.settings')
+      ->set('xml_map', ['drupal' => 'broken'])
+      ->save();
+
+    // This will retrieve broken updates.
+    $this->cronRun();
+    $this->drupalGet('admin/reports/status');
+    $this->assertSession()->statusCodeEquals(200);
+    $this->assertSession()->pageTextContains('There was a problem checking available updates for Drupal.');
+    $this->config('update_test.settings')
+      ->set('xml_map', ['drupal' => 'sec.0.2'])
+      ->save();
+    // Simulate the update_available_releases state expiring before cron is run
+    // and the state is used by \Drupal\update\UpdateManager::getProjects().
+    \Drupal::keyValueExpirable('update_available_releases')->deleteAll();
+    // This cron run should retrieve fixed updates.
+    $this->cronRun();
+    $this->drupalGet('admin/structure');
+    $this->assertSession()->statusCodeEquals(200);
+    $this->assertSession()->pageTextContains('There is a security update available for your version of Drupal.');
+  }
+
   /**
    * Tests messages when a project release is marked unsupported.
    *